Bump version to 4.11.0

Currently translated at 100.0% (4760 of 4760 strings)

Translation: pretix/pretix
Translate-URL: https://translate.pretix.eu/projects/pretix/pretix/de_Informal/

powered by weblate

.github/workflows/tests.yml

@@ -18,17 +18,17 @@ jobs:
     name: Tests
     strategy:
       matrix:
-        python-version: [3.6, 3.7, 3.8]
+        python-version: ["3.7", "3.8", "3.9"]
         database: [sqlite, postgres, mysql]
         exclude:
           - database: mysql
-            python-version: 3.7
-          - database: sqlite
-            python-version: 3.7
+            python-version: "3.8"
           - database: mysql
-            python-version: 3.6
+            python-version: "3.9"
           - database: sqlite
-            python-version: 3.6
+            python-version: "3.7"
+          - database: sqlite
+            python-version: "3.8"
     steps:
       - uses: actions/checkout@v2
       - uses: getong/mariadb-action@v1.1
@@ -55,7 +55,7 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-pip-
       - name: Install system dependencies
-        run: sudo apt update && sudo apt install gettext mysql-client
+        run: sudo apt update && sudo apt install gettext mariadb-client-10.3
       - name: Install Python dependencies
         run: pip3 install -e ".[dev]" mysqlclient psycopg2-binary
         working-directory: ./src

Dockerfile

@@ -31,7 +31,7 @@ RUN apt-get update && \
     echo 'pretixuser ALL=(ALL) NOPASSWD:SETENV: /usr/bin/supervisord' >> /etc/sudoers && \
     mkdir /static && \
     mkdir /etc/supervisord && \
-	curl -fsSL https://deb.nodesource.com/setup_15.x | sudo -E bash - && \
+	curl -fsSL https://deb.nodesource.com/setup_16.x | sudo -E bash - && \
     apt-get install -y nodejs && \
     curl -qL https://www.npmjs.com/install.sh | sh
 

doc/_themes/pretix_theme/layout.html

@@ -157,7 +157,7 @@
         <div class="rst-content">
           {% include "breadcrumbs.html" %}
           <div role="main" class="document" itemscope="itemscope" itemtype="http://schema.org/Article">
-           <div itemprop="articleBody">
+           <div itemprop="articleBody" class="section">
             {% block body %}{% endblock %}
            </div>
            <div class="articleComments">

doc/admin/config.rst

@@ -65,6 +65,9 @@ Example::
     A comma-separated list of plugins that are not available even though they are installed.
     Defaults to an empty string.
 
+``plugins_show_meta``
+    Whether to show authors and versions of plugins, defaults to ``on``.
+
 ``auth_backends``
     A comma-separated list of available auth backends. Defaults to ``pretix.base.auth.NativeAuthBackend``.
 
@@ -220,12 +223,30 @@ Example::
 ``user``, ``password``
     The SMTP user data to use for the connection. Empty by default.
 
+``tls``, ``ssl``
+    Use STARTTLS or SSL for the SMTP connection. Off by default.
+
 ``from``
     The email address to set as ``From`` header in outgoing emails by the system.
     Default: ``pretix@localhost``
 
-``tls``, ``ssl``
-    Use STARTTLS or SSL for the SMTP connection. Off by default.
+``from_notifications``
+    The email address to set as ``From`` header in admin notification emails by the system.
+    Defaults to the value of ``from``.
+
+``from_organizers``
+    The email address to set as ``From`` header in outgoing emails by the system sent on behalf of organizers.
+    Defaults to the value of ``from``.
+
+``custom_sender_verification_required``
+    If this is on (the default), organizers need to verify email addresses they want to use as senders in their event.
+
+``custom_sender_spf_string``
+    If this is set to a valid SPF string, pretix will show a warning if organizers use a sender address from a domain
+    that does not include this value.
+
+``custom_smtp_allow_private_networks``
+    If this is off (the default), custom SMTP servers cannot be private network addresses.
 
 ``admins``
     Comma-separated list of email addresses that should receive a report about every error code 500 thrown by pretix.
@@ -282,7 +303,7 @@ You can use an existing memcached server as pretix's caching backend::
 ``location``
     The location of memcached, either a host:port combination or a socket file.
 
-If no memcached is configured, pretix will use Django's built-in local-memory caching method.
+If no memcached is configured, pretix will use redis for caching. If neither is configured, pretix will not use any caching.
 
 .. note:: If you use memcached and you deploy pretix across multiple servers, you should use *one*
           shared memcached instance, not multiple ones, because cache invalidations would not be
@@ -445,8 +466,10 @@ You can configure the maximum file size for uploading various files::
     max_size_image = 12
     ; Max upload size for favicons in MiB, defaults to 1 MiB
     max_size_favicon = 2
-    ; Max upload size for email attachments in MiB, defaults to 10 MiB
+    ; Max upload size for email attachments of manually sent emails in MiB, defaults to 10 MiB
     max_size_email_attachment = 15
+    ; Max upload size for email attachments of automatically sent emails in MiB, defaults to 1 MiB
+    max_size_email_auto_attachment = 2
     ; Max upload size for other files in MiB, defaults to 10 MiB
     ; This includes all file upload type order questions
     max_size_other = 100

doc/admin/installation/docker_smallscale.rst

@@ -36,9 +36,6 @@ Linux and firewalls, we recommend that you start with `ufw`_.
           SSL certificates can be obtained for free these days. We also *do not* provide support for HTTP-only
           installations except for evaluation purposes.
 
-.. warning:: We recommend **PostgreSQL**. If you go for MySQL, make sure you run **MySQL 5.7 or newer** or
-             **MariaDB 10.2.7 or newer**.
-
 .. warning:: By default, using `ufw` in conjunction will not have any effect. Please make sure to either bind the exposed
              ports of your docker container explicitly to 127.0.0.1 or configure docker to respect any set up firewall
              rules.
@@ -61,6 +58,9 @@ directory writable to the user that runs pretix inside the docker container::
 Database
 --------
 
+.. warning:: **Please use PostgreSQL for all new installations**. If you need to go for MySQL, make sure you run
+             **MySQL 5.7 or newer** or **MariaDB 10.2.7 or newer**.
+
 Next, we need a database and a database user. We can create these with any kind of database managing tool or directly on
 our database's shell. Please make sure that UTF8 is used as encoding for the best compatibility. You can check this with
 the following command::
@@ -91,6 +91,8 @@ When using MySQL, make sure you set the character set of the database to ``utf8m
 
     mysql > CREATE DATABASE pretix DEFAULT CHARACTER SET utf8mb4 DEFAULT COLLATE utf8mb4_unicode_ci;
 
+You will also need to make sure that ``sql_mode`` in your ``my.cnf`` file does **not** include ``ONLY_FULL_GROUP_BY``.
+
 Redis
 -----
 
@@ -106,6 +108,18 @@ Now restart redis-server::
 
     # systemctl restart redis-server
 
+In this setup, systemd will delete ``/var/run/redis`` on every redis restart, which will cause issues with pretix. To
+prevent this, you can execute::
+
+   # systemctl edit redis-server
+
+And insert the following::
+
+    [Service]
+    # Keep the directory around so that pretix.service in docker does not need to be
+    # restarted when redis is restarted.
+    RuntimeDirectoryPreserve=yes
+
 .. warning:: Setting the socket permissions to 777 is a possible security problem. If you have untrusted users on your
              system or have high security requirements, please don't do this and let redis listen to a TCP socket
              instead. We recommend the socket approach because the TCP socket in combination with docker's networking

doc/admin/installation/manual_smallscale.rst

@@ -34,9 +34,6 @@ Linux and firewalls, we recommend that you start with `ufw`_.
           SSL certificates can be obtained for free these days. We also *do not* provide support for HTTP-only
           installations except for evaluation purposes.
 
-.. warning:: We recommend **PostgreSQL**. If you go for MySQL, make sure you run **MySQL 5.7 or newer** or
-             **MariaDB 10.2.7 or newer**.
-
 Unix user
 ---------
 
@@ -50,6 +47,9 @@ In this guide, all code lines prepended with a ``#`` symbol are commands that yo
 Database
 --------
 
+.. warning:: **Please use PostgreSQL for all new installations**. If you need to go for MySQL, make sure you run
+             **MySQL 5.7 or newer** or **MariaDB 10.2.7 or newer**.
+
 Having the database server installed, we still need a database and a database user. We can create these with any kind
 of database managing tool or directly on our database's shell. Please make sure that UTF8 is used as encoding for the
 best compatibility. You can check this with the following command::
@@ -65,6 +65,8 @@ When using MySQL, make sure you set the character set of the database to ``utf8m
 
     mysql > CREATE DATABASE pretix DEFAULT CHARACTER SET utf8mb4 DEFAULT COLLATE utf8mb4_unicode_ci;
 
+You will also need to make sure that ``sql_mode`` in your ``my.cnf`` file does **not** include ``ONLY_FULL_GROUP_BY``.
+
 Package dependencies
 --------------------
 
@@ -142,7 +144,7 @@ If you're running MySQL, also install the client library::
 
     (venv)$ pip3 install mysqlclient
 
-Note that you need Python 3.6 or newer. You can find out your Python version using ``python -V``.
+Note that you need Python 3.7 or newer. You can find out your Python version using ``python -V``.
 
 We also need to create a data directory::
 
@@ -259,14 +261,14 @@ The following snippet is an example on how to configure a nginx proxy for pretix
         }
 
         location /static/ {
-            alias /var/pretix/venv/lib/python3.7/site-packages/pretix/static.dist/;
+            alias /var/pretix/venv/lib/python3.10/site-packages/pretix/static.dist/;
             access_log off;
             expires 365d;
             add_header Cache-Control "public";
         }
     }
 
-.. note:: Remember to replace the ``python3.7`` in the ``/static/`` path in the config 
+.. note:: Remember to replace the ``python3.10`` in the ``/static/`` path in the config
           above with your python version.
 
 We recommend reading about setting `strong encryption settings`_ for your web server.

doc/api/deviceauth.rst

@@ -99,7 +99,8 @@ following endpoint:
        "hardware_brand": "Samsung",
        "hardware_model": "Galaxy S",
        "software_brand": "pretixdroid",
-       "software_version": "4.1.0"
+       "software_version": "4.1.0",
+       "info": {"arbitrary": "data"}
    }
 
 You will receive a response equivalent to the response of your initialization request.

doc/api/fundamentals.rst

@@ -43,6 +43,8 @@ Possible permissions are:
 * Can view vouchers
 * Can change vouchers
 
+.. _`rest-compat`:
+
 Compatibility
 -------------
 
@@ -58,6 +60,7 @@ that your clients can deal with them properly:
 * Support of new HTTP methods for a given API endpoint
 * Support of new query parameters for a given API endpoint
 * New fields contained in API responses
+* Response body structure or message texts on failed requests (``4xx``, ``5xx`` response codes)
 
 We treat the following types of changes as *backwards-incompatible*:
 

doc/api/guides/custom_checkout.rst

@@ -97,7 +97,8 @@ For example, if you want users to be redirected to ``https://example.org/order/r
 either enter ``https://example.org`` or ``https://example.org/order/``.
 
 The user will be redirected back to your page instead of pretix' order confirmation page after the payment,
-**regardless of whether it was successful or not**. Make sure you use our API to check if the payment actually
+**regardless of whether it was successful or not**. We will append an ``error=…`` query parameter with an error
+message, but you should not rely on that and instead make sure you use our API to check if the payment actually
 worked! Your final URL could look like this::
 
     https://test.pretix.eu/democon/3vjrh/order/NSLEZ/ujbrnsjzbq4dzhck/pay/123/?return_url=https%3A%2F%2Fexample.org%2Forder%2Freturn%3Ftx_id%3D1234

doc/api/resources/carts.rst

@@ -172,8 +172,6 @@ Cart position endpoints
 
        * does not check or calculate prices but believes any prices you send
 
-       * does not support the redemption of vouchers
-
        * does not prevent you from buying items that can only be bought with a voucher
 
        * does not support file upload questions
@@ -189,8 +187,9 @@ Cart position endpoints
    * ``attendee_email`` (optional)
    * ``subevent`` (optional)
    * ``expires`` (optional)
-   * ``includes_tax`` (optional)
+   * ``includes_tax`` (optional, **deprecated**, do not use, will be removed)
    * ``sales_channel`` (optional)
+   * ``voucher`` (optional, expect a voucher code)
    * ``answers``
 
       * ``question``

doc/api/resources/customers.rst

@@ -14,6 +14,7 @@ The customer resource contains the following public fields:
 Field                                 Type                       Description
 ===================================== ========================== =======================================================
 identifier                            string                     Internal ID of the customer
+external_identifier                   string                     External ID of the customer (or ``null``)
 email                                 string                     Customer email address
 name                                  string                     Name of this customer (or ``null``)
 name_parts                            object of strings          Decomposition of name (i.e. given name, family name)
@@ -24,6 +25,7 @@ last_login                            datetime                   Date and time o
 date_joined                           datetime                   Date and time of registration
 locale                                string                     Preferred language of the customer
 last_modified                         datetime                   Date and time of modification of the record
+notes                                 string                     Internal notes and comments (or ``null``)
 ===================================== ========================== =======================================================
 
 .. versionadded:: 4.0
@@ -58,6 +60,7 @@ Endpoints
         "results": [
           {
             "identifier": "8WSAJCJ",
+            "external_identifier": null,
             "email": "customer@example.org",
             "name": "John Doe",
             "name_parts": {
@@ -69,7 +72,8 @@ Endpoints
             "last_login": null,
             "date_joined": "2021-04-06T13:44:22.809216Z",
             "locale": "de",
-            "last_modified": "2021-04-06T13:44:22.809377Z"
+            "last_modified": "2021-04-06T13:44:22.809377Z",
+            "notes": null
           }
         ]
       }
@@ -103,6 +107,7 @@ Endpoints
 
       {
         "identifier": "8WSAJCJ",
+        "external_identifier": null,
         "email": "customer@example.org",
         "name": "John Doe",
         "name_parts": {
@@ -114,7 +119,8 @@ Endpoints
         "last_login": null,
         "date_joined": "2021-04-06T13:44:22.809216Z",
         "locale": "de",
-        "last_modified": "2021-04-06T13:44:22.809377Z"
+        "last_modified": "2021-04-06T13:44:22.809377Z",
+        "notes": null
       }
 
    :param organizer: The ``slug`` field of the organizer to fetch
@@ -150,6 +156,7 @@ Endpoints
 
       {
         "identifier": "8WSAJCJ",
+        "external_identifier": null,
         "email": "test@example.org",
         ...
       }
@@ -193,6 +200,7 @@ Endpoints
 
       {
         "identifier": "8WSAJCJ",
+        "external_identifier": null,
         "email": "test@example.org",
         …
       }
@@ -226,6 +234,7 @@ Endpoints
 
       {
         "identifier": "8WSAJCJ",
+        "external_identifier": null,
         "email": null,
         …
       }

doc/api/resources/discounts.rst

@@ -0,0 +1,306 @@
+.. _`rest-discounts`:
+
+Discounts
+=========
+
+Resource description
+--------------------
+
+Discounts provide a way to automatically reduce the price of a cart if it matches a given set of conditions.
+Discounts are available to everyone. If you want to give a discount just to specific persons, look at
+:ref:`vouchers <rest-vouchers>` instead. If you are interested in the behind-the-scenes details of how
+discounts are calculated for a specific order, have a look at :ref:`our algorithm documentation <algorithms-pricing>`.
+
+.. rst-class:: rest-resource-table
+
+======================================== ========================== =======================================================
+Field                                    Type                       Description
+======================================== ========================== =======================================================
+id                                       integer                    Internal ID of the discount rule
+active                                   boolean                    The discount will be ignored if this is ``false``
+internal_name                            string                     A name for the rule used in the backend
+position                                 integer                    An integer, used for sorting the rules which are applied in order
+sales_channels                           list of strings            Sales channels this discount is available on, such as
+                                                                    ``"web"`` or ``"resellers"``. Defaults to ``["web"]``.
+available_from                           datetime                   The first date time at which this discount can be applied
+                                                                    (or ``null``).
+available_until                          datetime                   The last date time at which this discount can be applied
+                                                                    (or ``null``).
+subevent_mode                            strings                    Determines how the discount is handled when used in an
+                                                                    event series. Can be ``"mixed"`` (no special effect),
+                                                                    ``"same"`` (discount is only applied for groups within
+                                                                    the same date), or ``"distinct"`` (discount is only applied
+                                                                    for groups with no two same dates).
+condition_all_products                   boolean                    If ``true``, the discount applies to all items.
+condition_limit_products                 list of integers           If ``condition_all_products`` is not set, this is a list
+                                                                    of internal item IDs that the discount applies to.
+condition_apply_to_addons                boolean                    If ``true``, the discount applies to add-on products as well,
+                                                                    otherwise it only applies to top-level items. The discount never
+                                                                    applies to bundled products.
+condition_ignore_voucher_discounted      boolean                    If ``true``, the discount does not apply to products which have
+                                                                    been discounted by a voucher.
+condition_min_count                      integer                    The minimum number of matching products for the discount
+                                                                    to be activated.
+condition_min_value                      money (string)             The minimum value of matching products for the discount
+                                                                    to be activated. Cannot be combined with ``condition_min_count``,
+                                                                    or with ``subevent_mode`` set to ``distinct``.
+benefit_discount_matching_percent        decimal (string)           The percentage of price reduction for matching products.
+benefit_only_apply_to_cheapest_n_matches integer                    If set higher than 0, the discount will only be applied to
+                                                                    the cheapest matches. Useful for a "3 for 2"-style discount.
+                                                                    Cannot be combined with ``condition_min_value``.
+======================================== ========================== =======================================================
+
+
+Endpoints
+---------
+
+.. http:get:: /api/v1/organizers/(organizer)/events/(event)/discounts/
+
+   Returns a list of all discounts within a given event.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      GET /api/v1/organizers/bigevents/events/sampleconf/discounts/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: application/json
+
+      {
+        "count": 1,
+        "next": null,
+        "previous": null,
+        "results": [
+          {
+            "id": 1,
+            "active": true,
+            "internal_name": "3 for 2",
+            "position": 1,
+            "sales_channels": ["web"],
+            "available_from": null,
+            "available_until": null,
+            "subevent_mode": "mixed",
+            "condition_all_products": true,
+            "condition_limit_products": [],
+            "condition_apply_to_addons": true,
+            "condition_ignore_voucher_discounted": false,
+            "condition_min_count": 3,
+            "condition_min_value": "0.00",
+            "benefit_discount_matching_percent": "100.00",
+            "benefit_only_apply_to_cheapest_n_matches": 1
+          }
+        ]
+      }
+
+   :query integer page: The page number in case of a multi-page result set, default is 1
+   :query boolean active: If set to ``true`` or ``false``, only discounts with this value for the field ``active`` will be
+                          returned.
+   :query string ordering: Manually set the ordering of results. Valid fields to be used are ``id`` and ``position``.
+                           Default: ``position``
+   :param organizer: The ``slug`` field of the organizer to fetch
+   :param event: The ``slug`` field of the event to fetch
+   :statuscode 200: no error
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer/event does not exist **or** you have no permission to view this resource.
+
+.. http:get:: /api/v1/organizers/(organizer)/events/(event)/discounts/(id)/
+
+   Returns information on one discount, identified by its ID.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      GET /api/v1/organizers/bigevents/events/sampleconf/discounts/1/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: application/json
+
+      {
+        "id": 1,
+        "active": true,
+        "internal_name": "3 for 2",
+        "position": 1,
+        "sales_channels": ["web"],
+        "available_from": null,
+        "available_until": null,
+        "subevent_mode": "mixed",
+        "condition_all_products": true,
+        "condition_limit_products": [],
+        "condition_apply_to_addons": true,
+        "condition_ignore_voucher_discounted": false,
+        "condition_min_count": 3,
+        "condition_min_value": "0.00",
+        "benefit_discount_matching_percent": "100.00",
+        "benefit_only_apply_to_cheapest_n_matches": 1
+      }
+
+   :param organizer: The ``slug`` field of the organizer to fetch
+   :param event: The ``slug`` field of the event to fetch
+   :param id: The ``id`` field of the discount to fetch
+   :statuscode 200: no error
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer/event does not exist **or** you have no permission to view this resource.
+
+.. http:post:: /api/v1/organizers/(organizer)/events/(event)/discounts/
+
+   Creates a new discount
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      POST /api/v1/organizers/bigevents/events/sampleconf/discounts/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+      Content-Type: application/json
+
+      {
+        "active": true,
+        "internal_name": "3 for 2",
+        "position": 1,
+        "sales_channels": ["web"],
+        "available_from": null,
+        "available_until": null,
+        "subevent_mode": "mixed",
+        "condition_all_products": true,
+        "condition_limit_products": [],
+        "condition_apply_to_addons": true,
+        "condition_ignore_voucher_discounted": false,
+        "condition_min_count": 3,
+        "condition_min_value": "0.00",
+        "benefit_discount_matching_percent": "100.00",
+        "benefit_only_apply_to_cheapest_n_matches": 1
+      }
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 201 Created
+      Vary: Accept
+      Content-Type: application/json
+
+      {
+        "id": 1,
+        "active": true,
+        "internal_name": "3 for 2",
+        "position": 1,
+        "sales_channels": ["web"],
+        "available_from": null,
+        "available_until": null,
+        "subevent_mode": "mixed",
+        "condition_all_products": true,
+        "condition_limit_products": [],
+        "condition_apply_to_addons": true,
+        "condition_ignore_voucher_discounted": false,
+        "condition_min_count": 3,
+        "condition_min_value": "0.00",
+        "benefit_discount_matching_percent": "100.00",
+        "benefit_only_apply_to_cheapest_n_matches": 1
+      }
+
+   :param organizer: The ``slug`` field of the organizer of the event to create a discount for
+   :param event: The ``slug`` field of the event to create a discount for
+   :statuscode 201: no error
+   :statuscode 400: The discount could not be created due to invalid submitted data.
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer/event does not exist **or** you have no permission to create this resource.
+
+.. http:patch:: /api/v1/organizers/(organizer)/events/(event)/discounts/(id)/
+
+   Update a discount. You can also use ``PUT`` instead of ``PATCH``. With ``PUT``, you have to provide all fields of
+   the resource, other fields will be reset to default. With ``PATCH``, you only need to provide the fields that you
+   want to change.
+
+   You can change all fields of the resource except the ``id`` field.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      PATCH /api/v1/organizers/bigevents/events/sampleconf/discounts/1/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+      Content-Type: application/json
+      Content-Length: 94
+
+      {
+        "active": false
+      }
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: application/json
+
+      {
+        "id": 1,
+        "active": false,
+        "internal_name": "3 for 2",
+        "position": 1,
+        "sales_channels": ["web"],
+        "available_from": null,
+        "available_until": null,
+        "subevent_mode": "mixed",
+        "condition_all_products": true,
+        "condition_limit_products": [],
+        "condition_apply_to_addons": true,
+        "condition_ignore_voucher_discounted": false,
+        "condition_min_count": 3,
+        "condition_min_value": "0.00",
+        "benefit_discount_matching_percent": "100.00",
+        "benefit_only_apply_to_cheapest_n_matches": 1
+      }
+
+   :param organizer: The ``slug`` field of the organizer to modify
+   :param event: The ``slug`` field of the event to modify
+   :param id: The ``id`` field of the discount to modify
+   :statuscode 200: no error
+   :statuscode 400: The discount could not be modified due to invalid submitted data
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer/event does not exist **or** you have no permission to change this resource.
+
+.. http:delete:: /api/v1/organizers/(organizer)/events/(event)/discount/(id)/
+
+   Delete a discount.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      DELETE /api/v1/organizers/bigevents/events/sampleconf/discount/1/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 204 No Content
+      Vary: Accept
+
+   :param organizer: The ``slug`` field of the organizer to modify
+   :param event: The ``slug`` field of the event to modify
+   :param id: The ``id`` field of the discount to delete
+   :statuscode 204: no error
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer/event does not exist **or** you have no permission to delete this resource.

doc/api/resources/index.rst

@@ -1,6 +1,11 @@
 Resources and endpoints
 =======================
 
+With a few exceptions, this only lists resources bundled in the pretix core modules.
+Additional endpoints are provided by pretix plugins. Some of them are documented
+at :ref:`plugin-docs`.
+
+
 .. toctree::
    :maxdepth: 2
 
@@ -19,6 +24,7 @@ Resources and endpoints
    orders
    invoices
    vouchers
+   discounts
    checkinlists
    waitinglist
    customers
@@ -33,4 +39,4 @@ Resources and endpoints
    exporters
    sendmail_rules
    billing_invoices
-   billing_var
+   billing_var

doc/api/resources/invoices.rst

@@ -58,6 +58,12 @@ lines                                 list of objects            The actual invo
                                                                  created before this field was introduced as well as for
                                                                  all lines not created by a product (e.g. a shipping or
                                                                  cancellation fee).
+├ subevent                            integer                    Event series date ID used to create this line. Note that everything
+                                                                 about the subevent might have changed since the creation
+                                                                 of the invoice. Can be ``null`` for all invoice lines
+                                                                 created before this field was introduced as well as for
+                                                                 all lines not created by a product (e.g. a shipping or
+                                                                 cancellation fee) as well as for all events that are not a series.
 ├ fee_type                            string                     Fee type, e.g. ``shipping``, ``service``, ``payment``,
                                                                  ``cancellation``, ``giftcard``, or ``other. Can be ``null`` for
                                                                  all invoice lines
@@ -120,6 +126,10 @@ internal_reference                    string                     Customer's refe
 
    The attribute ``lines.event_location`` has been added.
 
+.. versionchanged:: 4.6
+
+   The attribute ``lines.subevent`` has been added.
+
 
 Endpoints
 ---------
@@ -185,6 +195,7 @@ Endpoints
                 "description": "Budget Ticket",
                 "item": 1234,
                 "variation": 245,
+                "subevent": null,
                 "fee_type": null,
                 "fee_internal_type": null,
                 "event_date_from": "2017-12-27T10:00:00Z",
@@ -274,6 +285,7 @@ Endpoints
             "description": "Budget Ticket",
             "item": 1234,
             "variation": 245,
+            "subevent": null,
             "fee_type": null,
             "fee_internal_type": null,
             "event_date_from": "2017-12-27T10:00:00Z",

doc/api/resources/item_variations.rst

@@ -24,6 +24,9 @@ active                                boolean                    If ``false``, t
 description                           multi-lingual string       A public description of the variation. May contain
                                                                  Markdown syntax or can be ``null``.
 position                              integer                    An integer, used for sorting
+require_approval                      boolean                    If ``true``, orders with this variation will need to be
+                                                                 approved by the event organizer before they can be
+                                                                 paid.
 require_membership                    boolean                    If ``true``, booking this variation requires an active membership.
 require_membership_hidden             boolean                    If ``true`` and ``require_membership`` is set, this variation will
                                                                  be hidden from users without a valid membership.
@@ -76,6 +79,7 @@ Endpoints
               "en": "S"
             },
             "active": true,
+            "require_approval": false,
             "require_membership": false,
             "require_membership_hidden": false,
             "require_membership_types": [],
@@ -97,6 +101,7 @@ Endpoints
               "en": "L"
             },
             "active": true,
+            "require_approval": false,
             "require_membership": false,
             "require_membership_hidden": false,
             "require_membership_types": [],
@@ -147,6 +152,7 @@ Endpoints
         "price": "10.00",
         "original_price": null,
         "active": true,
+        "require_approval": false,
         "require_membership": false,
         "require_membership_hidden": false,
         "require_membership_types": [],
@@ -183,6 +189,7 @@ Endpoints
         "value": {"en": "Student"},
         "default_price": "10.00",
         "active": true,
+        "require_approval": false,
         "require_membership": false,
         "require_membership_hidden": false,
         "require_membership_types": [],
@@ -209,6 +216,7 @@ Endpoints
         "price": "10.00",
         "original_price": null,
         "active": true,
+        "require_approval": false,
         "require_membership": false,
         "require_membership_hidden": false,
         "require_membership_types": [],
@@ -266,6 +274,7 @@ Endpoints
         "price": "10.00",
         "original_price": null,
         "active": false,
+        "require_approval": false,
         "require_membership": false,
         "require_membership_hidden": false,
         "require_membership_types": [],

doc/api/resources/orders.rst

@@ -68,6 +68,7 @@ positions                             list of objects            List of order p
                                                                  non-canceled positions are included.
 fees                                  list of objects            List of fees included in the order total. By default, only
                                                                  non-canceled fees are included.
+├ id                                  integer                    Internal ID of the fee record
 ├ fee_type                            string                     Type of fee (currently ``payment``, ``passbook``,
                                                                  ``other``)
 ├ value                               money (string)             Fee amount
@@ -132,6 +133,14 @@ last_modified                         datetime                   Last modificati
 
    The ``item`` and ``variation`` query parameters have been added.
 
+.. versionchanged:: 4.6
+
+   The ``subevent`` query parameters has been added.
+
+.. versionchanged:: 4.8
+
+   The ``order.fees.id`` attribute has been added.
+
 
 .. _order-position-resource:
 
@@ -433,6 +442,7 @@ List of all orders
        recommend using this in combination with ``testmode=false``, since test mode orders can vanish at any time and
        you will not notice it using this method.
    :query datetime created_since: Only return orders that have been created since the given date.
+   :query integer subevent: Only return orders with a position that contains this subevent ID. *Warning:* Result will also include orders if they contain mixed subevents, and it will even return orders where the subevent is only contained in a canceled position.
    :query datetime subevent_after: Only return orders that contain a ticket for a subevent taking place after the given date. This is an exclusive after, and it considers the **end** of the subevent (or its start, if the end is not set).
    :query datetime subevent_before: Only return orders that contain a ticket for a subevent taking place after the given date. This is an exclusive before, and it considers the **start** of the subevent.
    :query string exclude: Exclude a field from the output, e.g. ``fees`` or ``positions.downloads``. Can be used as a performance optimization. Can be passed multiple times.
@@ -599,13 +609,17 @@ Fetching individual orders
 Order ticket download
 ---------------------
 
+.. versionchanged:: 4.10
+
+   The API now supports ticket downloads for pending orders if allowed by the event settings.
+
 .. http:get:: /api/v1/organizers/(organizer)/events/(event)/orders/(code)/download/(output)/
 
    Download tickets for an order, identified by its order code. Depending on the chosen output, the response might
    be a ZIP file, PDF file or something else. The order details response contains a list of output options for this
    particular order.
 
-   Tickets can be only downloaded if the order is paid and if ticket downloads are active. Note that in some cases the
+   Tickets can only be downloaded if ticket downloads are active and – depending on event settings – the order is either paid or pending. Note that in some cases the
    ticket file might not yet have been created. In that case, you will receive a status code :http:statuscode:`409` and
    you are expected to retry the request after a short period of waiting.
 
@@ -730,6 +744,37 @@ Generating new secrets
    :statuscode 401: Authentication failure
    :statuscode 403: The requested organizer/event does not exist **or** you have no permission to update this order.
 
+.. http:post:: /api/v1/organizers/(organizer)/events/(event)/orderpositions/(id)/regenerate_secrets/
+
+   Triggers generation of a new ``secret`` attribute for a single order position.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      POST /api/v1/organizers/bigevents/events/sampleconf/orderpositions/23/regenerate_secrets/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: application/json
+
+      (Full order position resource, see above.)
+
+   :param organizer: The ``slug`` field of the organizer of the event
+   :param event: The ``slug`` field of the event
+   :param code: The ``id`` field of the order position to update
+
+   :statuscode 200: no error
+   :statuscode 400: The order position could not be updated due to invalid submitted data.
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer/event does not exist **or** you have no permission to update this order position.
+
 Deleting orders
 ---------------
 
@@ -834,6 +879,7 @@ Creating orders
    * ``comment`` (optional)
    * ``custom_followup_at`` (optional)
    * ``checkin_attention`` (optional)
+   * ``require_approval`` (optional)
    * ``invoice_address`` (optional)
 
       * ``company``
@@ -893,8 +939,9 @@ Creating orders
 
    * ``force`` (optional). If set to ``true``, quotas will be ignored.
    * ``send_email`` (optional). If set to ``true``, the same emails will be sent as for a regular order, regardless of
-     whether these emails are enabled for certain sales channels. Defaults to
-     ``false``. Used to be ``send_mail`` before pretix 3.14.
+     whether these emails are enabled for certain sales channels. If set to ``null``, behavior will be controlled by pretix'
+     settings based on the sales channels (added in pretix 4.7). Defaults to ``false``.
+     Used to be ``send_mail`` before pretix 3.14.
 
    If you want to use add-on products, you need to set the ``positionid`` fields of all positions manually
    to incrementing integers starting with ``1``. Then, you can reference one of these
@@ -1039,6 +1086,9 @@ Order state operations
    will instead stay paid, but all positions will be removed (or marked as canceled) and replaced by the cancellation
    fee as the only component of the order.
 
+   You can control whether the customer is notified through ``send_email`` (defaults to ``true``).
+   You can pass a ``comment`` that can be visible to the user if it is used in the email template.
+
    **Example request**:
 
    .. sourcecode:: http
@@ -1050,6 +1100,7 @@ Order state operations
 
       {
           "send_email": true,
+          "comment": "Event was canceled.",
           "cancellation_fee": null
       }
 
@@ -1588,6 +1639,10 @@ Fetching individual positions
 Order position ticket download
 ------------------------------
 
+.. versionchanged:: 4.10
+
+   The API now supports ticket downloads for pending orders if allowed by the event settings.
+
 .. http:get:: /api/v1/organizers/(organizer)/events/(event)/orderpositions/(id)/download/(output)/
 
    Download tickets for one order position, identified by its internal ID.
@@ -1599,7 +1654,7 @@ Order position ticket download
    The referenced URL can provide a download or a regular, human-viewable website - so it is advised to open this URL
    in a webbrowser and leave it up to the user to handle the result.
 
-   Tickets can be only downloaded if the order is paid and if ticket downloads are active. Also, depending on event
+   Tickets can only be downloaded if ticket downloads are active and – depending on event settings – the order is either paid or pending. Also, depending on event
    configuration downloads might be only unavailable for add-on products or non-admission products.
    Note that in some cases the ticket file might not yet have been created. In that case, you will receive a status
    code :http:statuscode:`409` and you are expected to retry the request after a short period of waiting.
@@ -1635,6 +1690,8 @@ Order position ticket download
    :statuscode 409: The file is not yet ready and will now be prepared. Retry the request after waiting for a few
                     seconds.
 
+.. _rest-orderpositions-manipulate:
+
 Manipulating individual positions
 ---------------------------------
 
@@ -1642,6 +1699,11 @@ Manipulating individual positions
 
    The ``PATCH`` method has been added for individual positions.
 
+.. versionchanged:: 4.8
+
+   The ``PATCH`` method now supports changing items, variations, subevents, seats, prices, and tax rules.
+   The ``POST`` endpoint to add individual positions has been added.
+
 .. http:patch:: /api/v1/organizers/(organizer)/events/(event)/orderpositions/(id)/
 
    Updates specific fields on an order position. Currently, only the following fields are supported:
@@ -1668,6 +1730,21 @@ Manipulating individual positions
      and ``option_identifiers`` will be ignored. As a special case, you can submit the magic value
      ``"file:keep"`` as the answer to a file question to keep the current value without re-uploading it.
 
+   * ``item``
+
+   * ``variation``
+
+   * ``subevent``
+
+   * ``seat`` (specified as a string mapping to a ``string_guid``)
+
+   * ``price``
+
+   * ``tax_rule``
+
+   Changing parameters such as ``item`` or ``price`` will **not** automatically trigger creation of a new invoice,
+   you need to take care of that yourself.
+
    **Example request**:
 
    .. sourcecode:: http
@@ -1689,7 +1766,7 @@ Manipulating individual positions
       Vary: Accept
       Content-Type: application/json
 
-      (Full order resource, see above.)
+      (Full order position resource, see above.)
 
    :param organizer: The ``slug`` field of the organizer of the event
    :param event: The ``slug`` field of the event
@@ -1700,9 +1777,83 @@ Manipulating individual positions
    :statuscode 401: Authentication failure
    :statuscode 403: The requested organizer/event does not exist **or** you have no permission to update this order.
 
+.. http:post:: /api/v1/organizers/(organizer)/events/(event)/orderpositions/
+
+   Adds a new position to an order. Currently, only the following fields are supported:
+
+   * ``order`` (mandatory, specified as a string mapping to a ``code``)
+
+   * ``addon_to`` (optional, specified as an integer mapping to the ``positionid`` of the parent position)
+
+   * ``item`` (mandatory)
+
+   * ``variation`` (mandatory depending on item)
+
+   * ``subevent`` (mandatory depending on event)
+
+   * ``seat`` (specified as a string mapping to a ``string_guid``, mandatory depending on event and item)
+
+   * ``price`` (default price will be used if unset)
+
+   * ``attendee_email``
+
+   * ``attendee_name_parts`` or ``attendee_name``
+
+   * ``company``
+
+   * ``street``
+
+   * ``zipcode``
+
+   * ``city``
+
+   * ``country``
+
+   * ``state``
+
+   * ``answers``: Validation is handled the same way as when creating orders through the API. You are therefore
+     expected to provide ``question``, ``answer``, and possibly ``options``. ``question_identifier``
+     and ``option_identifiers`` will be ignored. As a special case, you can submit the magic value
+     ``"file:keep"`` as the answer to a file question to keep the current value without re-uploading it.
+
+   This will **not** automatically trigger creation of a new invoice, you need to take care of that yourself.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      POST /api/v1/organizers/bigevents/events/sampleconf/orderpositions/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+      Content-Type: application/json
+
+      {
+        "order": "ABC12",
+        "item": 5,
+        "addon_to": 1
+      }
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 201 Created
+      Vary: Accept
+      Content-Type: application/json
+
+      (Full order position resource, see above.)
+
+   :param organizer: The ``slug`` field of the organizer of the event
+   :param event: The ``slug`` field of the event
+
+   :statuscode 200: no error
+   :statuscode 400: The position could not be created due to invalid submitted data.
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer/event does not exist **or** you have no permission to create this position.
+
 .. http:delete:: /api/v1/organizers/(organizer)/events/(event)/orderpositions/(id)/
 
-   Deletes an order position, identified by its internal ID.
+   Cancels an order position, identified by its internal ID.
 
    **Example request**:
 
@@ -1728,6 +1879,128 @@ Manipulating individual positions
    :statuscode 403: The requested organizer/event does not exist **or** you have no permission to view this resource.
    :statuscode 404: The requested order position does not exist.
 
+Changing order contents
+-----------------------
+
+While you can :ref:`change positions individually <rest-orderpositions-manipulate>` sometimes it is necessary to make
+multiple changes to an order at once within one transaction. This makes it possible to e.g. swap the seats of two
+attendees in an order without running into conflicts. This interface also offers some possibilities not available
+otherwise, such as splitting an order or changing fees.
+
+.. versionchanged:: 4.8
+
+   This endpoint has been added to the system.
+
+.. http:post:: /api/v1/organizers/(organizer)/events/(event)/orders/(code)/change/
+
+   Performs a change operation on an order. You can supply the following fields:
+
+   * ``patch_positions``: A list of objects with the two keys ``position`` specifying an order position ID and
+     ``body`` specifying the desired changed values of the position (``item``, ``variation``, ``subevent``, ``seat``,
+     ``price``, ``tax_rule``).
+
+   * ``cancel_positions``: A list of objects with the single key ``position`` specifying an order position ID.
+
+   * ``split_positions``: A list of objects with the single key ``position`` specifying an order position ID.
+
+   * ``create_positions``: A list of objects describing new order positions with the same fields supported as when
+     creating them individually through the ``POST …/orderpositions/`` endpoint.
+
+   * ``patch_fees``: A list of objects with the two keys ``fee`` specifying an order fee ID and
+     ``body`` specifying the desired changed values of the position (``value``).
+
+   * ``cancel_fees``: A list of objects with the single key ``fee`` specifying an order fee ID.
+
+   * ``recalculate_taxes``: If set to ``"keep_net"``, all taxes will be recalculated based on the tax rule and invoice
+     address, the net price will be kept. If set to ``"keep_gross"``, the gross price will be kept. If set to ``null``
+     (the default) the taxes are not recalculated.
+
+   * ``send_email``: If set to ``true``, the customer will be notified about the change. Defaults to ``false``.
+
+   * ``reissue_invoice``: If set to ``true`` and an invoice exists for the order, it will be canceled and a new invoice
+     will be issued. Defaults to ``true``.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      POST /api/v1/organizers/bigevents/events/sampleconf/orders/ABC12/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+      Content-Type: application/json
+
+      {
+        "cancel_positions": [
+          {
+            "position": 12373
+          }
+        ],
+        "patch_positions": [
+          {
+            "position": 12374,
+            "body": {
+              "item": 12,
+              "variation": None,
+              "subevent": 562,
+              "seat": "seat-guid-2",
+              "price": "99.99",
+              "tax_rule": 15
+            }
+          }
+        ],
+        "split_positions": [
+          {
+            "position": 12375
+          }
+        ],
+        "create_positions": [
+          {
+            "item": 12,
+            "variation": None,
+            "subevent": 562,
+            "seat": "seat-guid-2",
+            "price": "99.99",
+            "addon_to": 12374,
+            "attendee_name": "Peter",
+          }
+        ],
+        "cancel_fees": [
+          {
+            "fee": 49
+          }
+        ],
+        "change_fees": [
+          {
+            "fee": 51,
+            "body": {
+              "value": "12.00"
+            }
+          }
+        ],
+        "reissue_invoice": true,
+        "send_email": true,
+        "recalculate_taxes": "keep_gross"
+      }
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: application/json
+
+      (Full order position resource, see above.)
+
+   :param organizer: The ``slug`` field of the organizer of the event
+   :param event: The ``slug`` field of the event
+   :param code: The ``code`` field of the order to update
+
+   :statuscode 200: no error
+   :statuscode 400: The order could not be updated due to invalid submitted data.
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer/event does not exist **or** you have no permission to update this order.
+
 
 Order payment endpoints
 -----------------------

doc/api/resources/subevents.rst

@@ -474,6 +474,7 @@ Endpoints
    :query is_future: If set to ``true`` (``false``), only events that happen currently or in the future are (not) returned.
    :query is_past: If set to ``true`` (``false``), only events that are over are (not) returned.
    :query ends_after: If set to a date and time, only events that happen during of after the given time are returned.
+   :query sales_channel: If set to a sales channel identifier, the response will only contain subevents from events available on this sales channel.
    :param organizer: The ``slug`` field of a valid organizer
    :param event: The ``slug`` field of the event to fetch
    :statuscode 200: no error

doc/api/resources/taxrules.rst

@@ -16,15 +16,22 @@ Field                                 Type                       Description
 ===================================== ========================== =======================================================
 id                                    integer                    Internal ID of the tax rule
 name                                  multi-lingual string       The tax rules' name
+internal_name                         string                     An optional name that is only used in the backend
 rate                                  decimal (string)           Tax rate in percent
 price_includes_tax                    boolean                    If ``true`` (default), tax is assumed to be included in
                                                                  the specified product price
 eu_reverse_charge                     boolean                    If ``true``, EU reverse charge rules are applied
 home_country                          string                     Merchant country (required for reverse charge), can be
                                                                  ``null`` or empty string
+keep_gross_if_rate_changes            boolean                    If ``true``, changes of the tax rate based on custom
+                                                                 rules keep the gross price constant (default is ``false``)
 ===================================== ========================== =======================================================
 
 
+.. versionchanged:: 4.6
+
+    The ``internal_name`` and ``keep_gross_if_rate_changes`` attributes have been added.
+
 Endpoints
 ---------
 
@@ -56,9 +63,11 @@ Endpoints
           {
             "id": 1,
             "name": {"en": "VAT"},
+            "internal_name": "VAT",
             "rate": "19.00",
             "price_includes_tax": true,
             "eu_reverse_charge": false,
+            "keep_gross_if_rate_changes": false,
             "home_country": "DE"
           }
         ]
@@ -94,9 +103,11 @@ Endpoints
       {
         "id": 1,
         "name": {"en": "VAT"},
+        "internal_name": "VAT",
         "rate": "19.00",
         "price_includes_tax": true,
         "eu_reverse_charge": false,
+        "keep_gross_if_rate_changes": false,
         "home_country": "DE"
       }
 
@@ -140,9 +151,11 @@ Endpoints
       {
         "id": 1,
         "name": {"en": "VAT"},
+        "internal_name": "VAT",
         "rate": "19.00",
         "price_includes_tax": true,
         "eu_reverse_charge": false,
+        "keep_gross_if_rate_changes": false,
         "home_country": "DE"
       }
 
@@ -185,9 +198,11 @@ Endpoints
       {
         "id": 1,
         "name": {"en": "VAT"},
+        "internal_name": "VAT",
         "rate": "20.00",
         "price_includes_tax": true,
         "eu_reverse_charge": false,
+        "keep_gross_if_rate_changes": false,
         "home_country": "DE"
       }
 

doc/api/resources/vouchers.rst

@@ -1,3 +1,5 @@
+.. _`rest-vouchers`:
+
 Vouchers
 ========
 

doc/development/algorithms/index.rst

@@ -2,12 +2,13 @@ Algorithms
 ==========
 
 The business logic inside pretix is full of complex algorithms making decisions based on all the hundreds of settings
-and input parameters available. Some of them are documented here as graphs, either because fully understanding them is very
+and input parameters available. Some of them are documented here as graphs, either because fully understanding them is very important
 when working on features close to them, or because they also need to be re-implemented by client-side components like our
 ticket scanning apps and we want to ensure the implementations are as similar as possible to avoid confusion.
 
 .. toctree::
    :maxdepth: 2
 
+   pricing
    checkin
    layouts

doc/development/algorithms/pricing.rst

@@ -0,0 +1,180 @@
+.. _`algorithms-pricing`:
+
+Pricing algorithms
+==================
+
+With pretix being an e-commerce application, one of its core tasks is to determine the price of a purchase. With the
+complexity allowed by our range of features, this is not a trivial task and there are many edge cases that need to be
+clearly defined. The most challenging part about this is that there are many situations in which a price might change
+while the user is going through the checkout process and we're learning more information about them or their purchase.
+For example, prices change when
+
+* The cart expires and the listed prices changed in the meantime
+* The user adds an invoice address that triggers a change in taxation
+* The user chooses a custom price for an add-on product and adjusts the price later on
+* The user adds a voucher to their cart
+* An automatic discount is applied
+
+For the purposes of this page, we're making a distinction between "naive prices" (which are just a plain number like 23.00), and
+"taxed prices" (which are a combination of a net price, a tax rate, and a gross price, like 19.33 + 19% = 23.00).
+
+Computation of listed prices
+----------------------------
+
+When showing a list of products, e.g. on the event front page, we always need to show a price. This price is what we
+call the "listed price" later on.
+
+To compute the listed price, we first use the ``default_price`` attribute of the ``Item`` that is being shown.
+If we are showing an ``ItemVariation`` and that variation has a ``default_price`` set on itself, the variation's price
+takes precedence and replaces the item's price.
+If we're in an event series and there exists a ``SubEventItem`` or ``SubEventItemVariation`` with a price set, the
+subevent's price configuration takes precedence over both the item as well as the variation and replaces the listed price.
+
+Listed prices are naive prices. Before we actually show them to the user, we need to check if ``TaxRule.price_includes_tax``
+is set to determine if we need to add tax or subtract tax to get to the taxed price. We then consider the event's
+``display_net_prices`` setting to figure out which way to present the taxed price in the interface.
+
+Guarantees on listed prices
+---------------------------
+
+One goal of all further logic is that if a user sees a listed price, they are guaranteed to get the product at that
+price as long as they complete their purchase within the cart expiration time frame. For example, if the cart expiration
+time is set to 30 minutes and someone puts a item listed at €23 in their cart at 4pm, they can still complete checkout
+at €23 until 4.30pm, even if the organizer decides to raise the price to €25 at 4.10pm. If they complete checkout after
+4.30pm, their cart will be adjusted to the new price and the user will see a warning that the price has changed.
+
+Computation of cart prices
+--------------------------
+
+Input
+"""""
+
+To ensure the guarantee mentioned above, even in the light of all possible dynamic changes, the ``listed_price``
+is explicitly stored in the ``CartPosition`` model after the item has been added to the cart.
+
+If ``Item.free_price`` is set, the user is allowed to voluntarily increase the price. In this case, the user's input
+is stored as ``custom_price_input`` without much further validation for use further down below in the process.
+If ``display_net_prices`` is set, the user's input is also considered to be a net price and ``custom_price_input_is_net``
+is stored for the cart position. In any other case, the user's input is considered to be a gross price based on the tax
+rules' default tax rate.
+
+The computation of prices in the cart always starts from the ``listed_price``. The ``list_price`` is only computed
+when adding the product to the cart or when extending the cart's lifetime after it expired. All other steps such as
+creating an order based on the cart trust ``list_price`` without further checks.
+
+Vouchers
+""""""""
+
+As a first step, the cart is checked for any voucher that should be applied to the position. If such a voucher exists,
+it's discount (percentage or fixed) is applied to the listed price. The result of this is stored to ``price_after_voucher``.
+Since ``listed_price`` naive, ``price_after_voucher`` is naive as well. As a consequence, if you have a voucher configured
+to "set the price to €10", it depends on ``TaxRule.price_includes_tax`` again whether this is €10 including or excluding
+taxes.
+
+The ``price_after_voucher`` is only computed when adding the product to the cart or when extending the cart's
+lifetime after it expired. It is also checked again when the order is created, since the available discount might have
+changed due to the voucher's budget being (almost) exhausted.
+
+Line price
+""""""""""
+
+The next step computes the final price of this position if it is the only position in the cart. This happens in "reverse
+order", i.e. before the computation can be performed for a cart position, the step needs to be performed on all of its
+bundled positions. The sum of ``price_after_voucher`` of all bundled positions is now called ``bundled_sum``.
+
+First, the value from ``price_after_voucher`` will be processed by the applicable ``TaxRule.tax()`` (which is complex
+in itself but is not documented here in detail at the moment).
+
+If ``custom_price_input`` is not set, ``bundled_sum`` will be subtracted from the gross price and the net price is
+adjusted accordingly. The result is stored as ``tax_rate`` and ``line_price_gross`` in the cart position.
+
+If ``custom_price_input`` is set, the value will be compared to either the gross or the net value of the ``tax()``
+result, depending on ``custom_price_input_is_net``. If the comparison yields that the custom price is higher, ``tax()``
+will be called again . Then, ``bundled_sum`` will be subtracted from the gross price and the result is stored like
+above.
+
+The computation of ``line_price_gross`` from ``price_after_voucher``, ``custom_price_input``, and tax settings
+is repeated after every change of anything in the cart or after every change of the invoice address.
+
+Discounts
+---------
+
+After ``line_price_gross`` has been computed for all positions, the discount engine will run to apply any automatic
+discounts. Organizers can add rules for automatic discounts in the pretix backend. These rules are ordered and
+will be applied in order. Every cart position can only be "used" by one discount rule. "Used" can either mean that
+the price of the position was actually discounted, but it can also mean that the position was required to enable
+a discount for a different position, e.g. in case of a "buy 3 for the price of 2" offer.
+
+The algorithm for applying an individual discount rule first starts with eliminating all products that do not match
+the rule based on its product scope. Then, the algorithm is handled differently for different configurations.
+
+Case 1: Discount based on minimum value without respect to subevents
+""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
+
+* Check whether the gross sum of all positions is at least ``condition_min_value``, otherwise abort.
+
+* Reduce the price of all positions by ``benefit_discount_matching_percent``.
+
+* Mark all positions as "used" to hide them from further rules
+
+Case 2: Discount based on minimum number of tickets without respect to subevents
+""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
+
+* Check whether the number of all positions is at least ``condition_min_count``, otherwise abort.
+
+* If ``benefit_only_apply_to_cheapest_n_maches`` is set,
+
+    * Sort all positions by price.
+    * Reduce the price of the first ``n_positions // condition_min_count * benefit_only_apply_to_cheapest_n_matches`` positions by ``benefit_discount_matching_percent``.
+    * Mark the first ``n_positions // condition_min_count * condition_min_count`` as "used" to hide them from further rules.
+    * Mark all positions as "used" to hide them from further rules.
+
+* Else,
+
+    * Reduce the price of all positions by ``benefit_discount_matching_percent``.
+    * Mark all positions as "used" to hide them from further rules.
+
+Case 3: Discount only for products of the same subevent
+"""""""""""""""""""""""""""""""""""""""""""""""""""""""
+
+* Split the cart into groups based on the subevent.
+
+* Proceed with case 1 or 2 for every group.
+
+Case 4: Discount only for products of distinct subevents
+""""""""""""""""""""""""""""""""""""""""""""""""""""""""
+
+* Let ``subevents`` be a list of distinct subevents in the cart.
+
+* Let ``positions[subevent]`` be a list of positions for every subevent.
+
+* Let ``current_group`` be the current group and ``groups`` the list of all groups.
+
+* Repeat
+
+    * Order ``subevents`` by the length of their ``positions[subevent]`` list, starting with the longest list.
+      Do not count positions that are part of ``current_group`` already.
+
+    * Let ``candidates`` be the concatenation of all ``positions[subevent]`` lists with the same length as the
+      longest list.
+
+    * If ``candidates`` is empty, abort the repetition.
+
+    * Order ``candidates`` by their price, starting with the lowest price.
+
+    * Pick one entry from ``candidates`` and put it into ``current_group``. If ``current_group`` is shorter than
+      ``benefit_only_apply_to_cheapest_n_matches``, we pick from the start (lowest price), otherwise we pick from
+      the end (highest price)
+
+    * If ``current_group`` is now ``condition_min_count``, remove all entries from ``current_group`` from
+      ``positions[…]``, add ``current_group`` to ``groups``, and reset ``current_group`` to an empty group.
+
+* For every position still left in a ``positions[…]`` list, try if there is any ``group`` in groups that it can
+  still be added to without violating the rule of distinct subevents
+
+* For every group in ``groups``, proceed with case 1 or 2.
+
+Flowchart
+---------
+
+.. image:: /images/cart_pricing.png

doc/development/api/auth.rst

@@ -20,20 +20,31 @@ Basically, three pre-defined flows are supported:
 * Authentication mechanisms that rely on **redirection**, e.g. to an OAuth provider. These can be implemented by
   supplying a ``authentication_url`` method and implementing a custom return view.
 
-Authentication backends are *not* collected through a signal. Instead, they must explicitly be set through the
-``auth_backends`` directive in the ``pretix.cfg`` :ref:`configuration file <config>`.
+For security reasons, authentication backends are *not* automatically discovered through a signal. Instead, they must
+explicitly be set through the ``auth_backends`` directive in the ``pretix.cfg`` :ref:`configuration file <config>`.
 
-In each of these methods (``form_authenticate``, ``request_authenticate`` or your custom view) you are supposed to
-either get an existing :py:class:`pretix.base.models.User` object from the database or create a new one. There are a
-few rules you need to follow:
+In each of these methods (``form_authenticate``, ``request_authenticate``, or your custom view) you are supposed to
+use ``User.objects.get_or_create_for_backend`` to get a :py:class:`pretix.base.models.User` object from the database
+or create a new one.
 
-* You **MUST** only return users with the ``auth_backend`` attribute set to the ``identifier`` value of your backend.
+There are a few rules you need to follow:
 
-* You **MUST** create new users with the ``auth_backend`` attribute set to the ``identifier`` value of your backend.
+* You **MUST** have some kind of identifier for a user that is globally unique and **SHOULD** never change, even if the
+  user's name or email address changes. This could e.g. be the ID of the user in an external database. The identifier
+  must not be longer than 190 characters. If you worry your backend might generated longer identifiers, consider
+  using a hash function to trim them to a constant length.
+
+* You **SHOULD** not allow users created by other authentication backends to log in through your code, and you **MUST**
+  only create, modify or return users with ``auth_backend`` set to your backend.
 
 * Every user object **MUST** have an email address. Email addresses are globally unique. If the email address is
   already registered to a user who signs in through a different backend, you **SHOULD** refuse the login.
 
+``User.objects.get_or_create_for_backend`` will follow these rules for you automatically. It works like this:
+
+.. autoclass:: pretix.base.models.auth.UserManager
+   :members: get_or_create_for_backend
+
 The backend interface
 ---------------------
 
@@ -59,6 +70,7 @@ The backend interface
 
    .. automethod:: authentication_url
 
+
 Logging users in
 ----------------
 
@@ -68,3 +80,45 @@ recommend that you use the following utility method to correctly set session val
 authentication (if activated):
 
 .. autofunction:: pretix.control.views.auth.process_login
+
+A custom view that is called after a redirect from an external identity provider could look like this::
+
+   from django.contrib import messages
+   from django.shortcuts import redirect
+   from django.urls import reverse
+
+   from pretix.base.models import User
+   from pretix.base.models.auth import EmailAddressTakenError
+   from pretix.control.views.auth import process_login
+
+
+   def return_view(request):
+       # Verify validity of login with the external provider's API
+       api_response = my_verify_login_function(
+           code=request.GET.get('code')
+       )
+
+       try:
+           u = User.objects.get_or_create_for_backend(
+               'my_backend_name',
+               api_response['userid'],
+               api_response['email'],
+               set_always={
+                   'fullname': '{} {}'.format(
+                       api_response.get('given_name', ''),
+                       api_response.get('family_name', ''),
+                   ),
+               },
+               set_on_creation={
+                   'locale': api_response.get('locale').lower()[:2],
+                   'timezone': api_response.get('zoneinfo', 'UTC'),
+               }
+           )
+       except EmailAddressTakenError:
+           messages.error(
+               request, _('We cannot create your user account as a user account in this system '
+                          'already exists with the same email address.')
+           )
+           return redirect(reverse('control:auth.login'))
+       else:
+           return process_login(request, u, keep_logged_in=False)

doc/development/api/cookieconsent.rst

@@ -0,0 +1,119 @@
+.. highlight:: python
+   :linenothreshold: 5
+
+.. _`cookieconsent`:
+
+Handling cookie consent
+=======================
+
+pretix includes an optional feature to handle cookie consent explicitly to comply with EU regulations.
+If your plugin sets non-essential cookies or includes a third-party service that does so, you should
+integrate with this feature.
+
+Server-side integration
+-----------------------
+
+First, you need to declare that you are using non-essential cookies by responding to the following
+signal:
+
+.. automodule:: pretix.presale.signals
+   :members: register_cookie_providers
+
+You are expected to return a list of ``CookieProvider`` objects instantiated from the following class:
+
+.. class:: pretix.presale.cookies.CookieProvider
+
+   .. py:attribute:: CookieProvider.identifier
+
+      A short and unique identifier used to distinguish this cookie provider form others (required).
+
+   .. py:attribute:: CookieProvider.provider_name
+
+      A human-readable name of the entity of feature responsible for setting the cookie (required).
+
+   .. py:attribute:: CookieProvider.usage_classes
+
+      A list of enum values from the ``pretix.presale.cookies.UsageClass`` enumeration class, such as
+      ``UsageClass.ANALYTICS``, ``UsageClass.MARKETING``, or ``UsageClass.SOCIAL`` (required).
+
+   .. py:attribute:: CookieProvider.privacy_url
+
+      A link to a privacy policy (optional).
+
+Here is an example of such a receiver:
+
+.. code-block:: python
+
+   @receiver(register_cookie_providers)
+   def recv_cookie_providers(sender, request, **kwargs):
+       return [
+           CookieProvider(
+               identifier='google_analytics',
+               provider_name='Google Analytics',
+               usage_classes=[UsageClass.ANALYTICS],
+           )
+       ]
+
+JavaScript-side integration
+---------------------------
+
+The server-side integration only causes the cookie provider to show up in the cookie dialog. You still
+need to care about actually enforcing the consent state.
+
+You can access the consent state through the ``window.pretix.cookie_consent`` variable. Whenever the
+value changes, a ``pretix:cookie-consent:change`` event is fired on the ``document`` object.
+
+The variable will generally have one of the following states:
+
+.. rst-class:: rest-resource-table
+
+================================================================ =====================================================
+State                                                            Interpretation
+================================================================ =====================================================
+``pretix === undefined || pretix.cookie_consent === undefined``  Your JavaScript has loaded before the cookie consent
+                                                                 script. Wait for the event to be fired, then try again,
+                                                                 do not yet set a cookie.
+``pretix.cookie_consent === null``                               The cookie consent mechanism has not been enabled. This
+                                                                 usually means that you can set cookies however you like.
+``pretix.cookie_consent[identifier] === undefined``              The cookie consent mechanism is loaded, but has no data
+                                                                 on your cookie yet, wait for the event to be fired, do not
+                                                                 yet set a cookie.
+``pretix.cookie_consent[identifier] === true``                   The user has consented to your cookie.
+``pretix.cookie_consent[identifier] === false``                  The user has actively rejected your cookie.
+================================================================ =====================================================
+
+If you are integrating e.g. a tracking provider with native cookie consent support such
+as Facebook's Pixel, you can integrate it like this:
+
+.. code-block:: javascript
+
+     var consent = (window.pretix || {}).cookie_consent;
+     if (consent !== null && !(consent || {}).facebook) {
+         fbq('consent', 'revoke');
+     }
+     fbq('init', ...);
+     document.addEventListener('pretix:cookie-consent:change', function (e) {
+         fbq('consent', (e.detail || {}).facebook ? 'grant' : 'revoke');
+     })
+
+If you have a JavaScript function that you only want to load if consent for a specific ``identifier``
+is given, you can wrap it like this:
+
+.. code-block:: javascript
+
+     var consent_identifier = "youridentifier";
+     var consent = (window.pretix || {}).cookie_consent;
+     if (consent === null || (consent || {})[consent_identifier] === true) {
+         // Cookie consent tool is either disabled or consent is given
+         addScriptElement(src);
+         return;
+     }
+
+     // Either cookie consent tool has not loaded yet or consent is not given
+     document.addEventListener('pretix:cookie-consent:change', function onChange(e) {
+         var consent = e.detail || {};
+         if (consent === null || consent[consent_identifier] === true) {
+             addScriptElement(src);
+             document.removeEventListener('pretix:cookie-consent:change', onChange);
+         }
+     })

doc/development/api/index.rst

@@ -17,6 +17,7 @@ Contents:
    shredder
    import
    customview
+   cookieconsent
    auth
    general
    quality

doc/development/api/payment.rst

@@ -62,6 +62,8 @@ The provider class
 
    .. autoattribute:: public_name
 
+   .. autoattribute:: confirm_button_name
+
    .. autoattribute:: is_enabled
 
    .. autoattribute:: priority

doc/development/api/plugins.rst

@@ -45,13 +45,17 @@ Attribute          Type                 Description
 name               string               The human-readable name of your plugin
 author             string               Your name
 version            string               A human-readable version code of your plugin
-description        string               A more verbose description of what your plugin does.
+description        string               A more verbose description of what your plugin does. May contain HTML.
 category           string               Category of a plugin. Either one of ``"FEATURE"``, ``"PAYMENT"``,
                                         ``"INTEGRATION"``, ``"CUSTOMIZATION"``, ``"FORMAT"``, or ``"API"``,
                                         or any other string.
+picture            string (optional)    Path to a picture resolvable through the static file system.
+featured           boolean (optional)   ``False`` by default, can promote a plugin if it's something many users will want, use carefully.
 visible            boolean (optional)   ``True`` by default, can hide a plugin so it cannot be normally activated.
 restricted         boolean (optional)   ``False`` by default, restricts a plugin such that it can only be enabled
                                         for an event by system administrators / superusers.
+experimental       boolean (optional)   ``False`` by default, marks a plugin as an experimental feature in the plugins list.
+picture            string (optional)    Path to a picture resolvable through the static file system.
 compatibility      string               Specifier for compatible pretix versions.
 ================== ==================== ===========================================================
 
@@ -74,8 +78,10 @@ A working example would be:
             name = _("PayPal")
             author = _("the pretix team")
             version = '1.0.0'
-            category = 'PAYMENT
+            category = 'PAYMENT'
+            picture = 'pretix_paypal/paypal_logo.svg'
             visible = True
+            featured = False
             restricted = False
             description = _("This plugin allows you to receive payments via PayPal")
             compatibility = "pretix>=2.7.0"
@@ -92,6 +98,7 @@ those will be displayed but not block the plugin execution.
 
 The ``AppConfig`` class may implement a method ``is_available(event)`` that checks if a plugin
 is available for a specific event. If not, it will not be shown in the plugin list of that event.
+You should not define ``is_available`` and ``restricted`` on the same plugin.
 
 Plugin registration
 -------------------

doc/images/cart_pricing.puml

@@ -0,0 +1,28 @@
+@startuml
+
+partition "For every cart position" {
+    (*) --> "Get default price from product"
+    --> if "Product has variations?" then
+        -->[yes] "Override with price from variation"
+        --> if "Event series?" then
+            -->[yes] "Override with price from subevent"
+            -down-> "Store as listed_price"
+        else
+            -down->[no] "Store as listed_price"
+        endif
+    else
+        -down->[no] "Store as listed_price"
+    endif
+    --> if "Voucher applied?" then
+        -->[yes] "Apply voucher pricing"
+        --> "Store as price_after_voucher"
+    else
+        -->[no] "Store as price_after_voucher"
+    endif
+    --> "Apply custom price if product allows\nApply tax rule\nSubtract bundled products"
+    --> "Store as line_price (gross), tax_rate"
+}
+--> "Apply discount engine"
+--> "Store as price (gross)"
+
+@enduml

doc/plugins/digital.rst

@@ -52,6 +52,7 @@ Variable                            Description
 ``order_email``                     E-mail address of the ticket purchaser
 ``product_id``                      Internal ID of the purchased product
 ``product_variation``               Internal ID of the purchased product variation (or empty)
+``secret``                          The secret ticket code, would be used as the QR code for physical tickets
 ``attendee_name``                   Full name of the ticket holder (or empty)
 ``attendee_name_*``                 Name parts of the ticket holder, depending on configuration, e.g. ``attendee_name_given_name`` or ``attendee_name_family_name``
 ``attendee_email``                  E-mail address of the ticket holder (or empty)
@@ -61,7 +62,7 @@ Variable                            Description
 ``attendee_city``                   City of the ticket holder's address (or empty)
 ``attendee_country``                Country code of the ticket holder's address (or empty)
 ``attendee_state``                  State of the ticket holder's address (or empty)
-``answer[XYZ]``                     Answer to the custom question with identifier ``XYZ``
+``answers[XYZ]``                    Answer to the custom question with identifier ``XYZ``
 ``invoice_name``                    Full name of the invoice address (or empty)
 ``invoice_name_*``                  Name parts of the invoice address, depending on configuration, e.g. ``invoice_name_given_name`` or ``invoice_name_family_name``
 ``invoice_company``                 Company of the invoice address (or empty)

doc/plugins/exhibitors.rst

@@ -0,0 +1,732 @@
+Exhibitors
+==========
+
+The exhibitors plugin allows to manage exhibitors at your trade show or conference. After signing up your exhibitors
+in the system, you can assign vouchers to exhibitors and give them access to the data of these vouchers. The exhibitors
+module is also the basis of the pretixLEAD lead scanning application.
+
+.. note:: On pretix Hosted, using the lead scanning feature of the exhibitors plugin can add additional costs
+          depending on your contract.
+
+The plugin exposes two APIs. One (REST API) is intended for bulk-data operations from the admin side, and one
+(App API) that is used by the pretixLEAD app.
+
+REST API
+---------
+
+The REST API for exhibitors requires the usual :ref:`rest-auth`.
+
+Resources
+"""""""""
+
+The exhibitors plugin provides a HTTP API that allows you to create new exhibitors.
+
+The exhibitors resource contains the following public fields:
+
+.. rst-class:: rest-resource-table
+
+===================================== ========================== =======================================================
+Field                                 Type                       Description
+===================================== ========================== =======================================================
+id                                    integer                    Internal exhibitor ID in pretix
+name                                  string                     Exhibitor name
+internal_id                           string                     Can be used for the ID in your exhibition system, your customer ID, etc. Can be ``null``. Maximum 255 characters.
+contact_name                          string                     Contact person (or ``null``)
+contact_name_parts                    object of strings          Decomposition of contact name (i.e. given name, family name)
+contact_email                         string                     Contact person email address (or ``null``)
+booth                                 string                     Booth number (or ``null``). Maximum 100 characters.
+locale                                string                     Locale for communication with the exhibitor (or ``null``).
+access_code                           string                     Access code for the exhibitor to access their data or use the lead scanning app (read-only).
+allow_lead_scanning                   boolean                    Enables lead scanning app
+allow_lead_access                     boolean                    Enables access to data gathered by the lead scanning app
+allow_voucher_access                  boolean                    Enables access to data gathered by exhibitor vouchers
+comment                               string                     Internal comment, not shown to exhibitor
+===================================== ========================== =======================================================
+
+You can also access the scanned leads through the API which contains the following public fields:
+
+.. rst-class:: rest-resource-table
+
+===================================== ========================== =======================================================
+Field                                 Type                       Description
+===================================== ========================== =======================================================
+attendee_order                        string                     Order code of the order the scanned attendee belongs to
+attendee_positionid                   integer                    ``positionid`` if the attendee within the order specified by ``attendee_order``
+rating                                integer                    A rating of 0 to 5 stars (or ``null``)
+notes                                 string                     A note taken by the exhibitor after scanning
+tags                                  list of strings            Additional tags selected by the exhibitor
+first_upload                          datetime                   Date and time of the first upload of this lead
+data                                  list of objects            Attendee data set that may be shown to the exhibitor based o
+                                                                 the event's configuration. Each entry contains the fields ``id``,
+                                                                 ``label``, ``value``, and ``details``. ``details`` is usually empty
+                                                                 except in a few cases where it contains an additional list of objects
+                                                                 with ``value`` and ``label`` keys (e.g. splitting of names).
+device_name                           string                     User-defined name for the device used for scanning (or ``null``).
+===================================== ========================== =======================================================
+
+Endpoints
+"""""""""
+
+.. http:get:: /api/v1/organizers/(organizer)/events/(event)/exhibitors/
+
+   Returns a list of all exhibitors configured for an event.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      GET /api/v1/organizers/bigevents/events/sampleconf/exhibitors/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: application/json
+
+      {
+        "count": 1,
+        "next": null,
+        "previous": null,
+        "results": [
+          {
+            "id": 1,
+            "name": "Aperture Science",
+            "internal_id": null,
+            "contact_name": "Dr Cave Johnson",
+            "contact_name_parts": {
+                "_scheme": "salutation_title_given_family",
+                "family_name": "Johnson",
+                "given_name": "Cave",
+                "salutation": "",
+                "title": "Dr"
+            },
+            "contact_email": "johnson@as.example.org",
+            "booth": "A2",
+            "locale": "de",
+            "access_code": "VKHZ2FU8",
+            "allow_lead_scanning": true,
+            "allow_lead_access": true,
+            "allow_voucher_access": true,
+            "comment": ""
+          }
+        ]
+      }
+
+   :query page: The page number in case of a multi-page result set, default is 1
+   :param organizer: The ``slug`` field of a valid organizer
+   :param event: The ``slug`` field of the event to fetch
+   :statuscode 200: no error
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer or event does not exist **or** you have no permission to view it.
+
+.. http:get:: /api/v1/organizers/(organizer)/events/(event)/exhibitors/(id)/
+
+   Returns information on one exhibitor, identified by its ID.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      GET /api/v1/organizers/bigevents/events/sampleconf/exhibitors/1/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: application/json
+
+      {
+        "id": 1,
+        "name": "Aperture Science",
+        "internal_id": null,
+        "contact_name": "Dr Cave Johnson",
+        "contact_name_parts": {
+            "_scheme": "salutation_title_given_family",
+            "family_name": "Johnson",
+            "given_name": "Cave",
+            "salutation": "",
+            "title": "Dr"
+        },
+        "contact_email": "johnson@as.example.org",
+        "booth": "A2",
+        "locale": "de",
+        "access_code": "VKHZ2FU8",
+        "allow_lead_scanning": true,
+        "allow_lead_access": true,
+        "allow_voucher_access": true,
+        "comment": ""
+      }
+
+   :param organizer: The ``slug`` field of the organizer to fetch
+   :param event: The ``slug`` field of the event to fetch
+   :param id: The ``id`` field of the exhibitor to fetch
+   :statuscode 200: no error
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer/event/exhibitor does not exist **or** you have no permission to view it.
+
+.. http:get:: /api/v1/organizers/(organizer)/events/(event)/exhibitors/(id)/leads/
+
+   Returns a list of all scanned leads of an exhibitor.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      GET /api/v1/organizers/bigevents/events/sampleconf/exhibitors/1/leads/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: application/json
+
+      {
+        "count": 1,
+        "next": null,
+        "previous": null,
+        "results": [
+          {
+            "attendee_order": "T0E7E",
+            "attendee_positionid": 1,
+            "rating": 1,
+            "notes": "",
+            "tags": [],
+            "first_upload": "2021-07-06T11:03:31.414491+01:00",
+            "data": [
+              {
+                "id": "attendee_name",
+                "label": "Attendee name",
+                "value": "Peter Miller",
+                "details": [
+                  {"label": "Given name", "value": "Peter"},
+                  {"label": "Family name", "value": "Miller"},
+                ]
+              }
+            ]
+          }
+        ]
+      }
+
+   :query page: The page number in case of a multi-page result set, default is 1
+   :param organizer: The ``slug`` field of a valid organizer
+   :param event: The ``slug`` field of the event to fetch
+   :param id: The ``id`` field of the exhibitor to fetch
+   :statuscode 200: no error
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer or event or exhibitor does not exist **or** you have no permission to view it.
+
+.. http:get:: /api/v1/organizers/(organizer)/events/(event)/exhibitors/(id)/vouchers/
+
+   Returns a list of all vouchers connected to an exhibitor. The response contains the same data as described in
+   :ref:`rest-vouchers`.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      GET /api/v1/organizers/bigevents/events/sampleconf/exhibitors/1/vouchers/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: application/json
+
+      {
+        "count": 1,
+        "next": null,
+        "previous": null,
+        "results": [
+          {
+            "id": 1,
+            "code": "43K6LKM37FBVR2YG",
+            "max_usages": 1,
+            "redeemed": 0,
+            "valid_until": null,
+            "block_quota": false,
+            "allow_ignore_quota": false,
+            "price_mode": "set",
+            "value": "12.00",
+            "item": 1,
+            "variation": null,
+            "quota": null,
+            "tag": "testvoucher",
+            "comment": "",
+            "seat": null,
+            "subevent": null
+          }
+        ]
+      }
+
+   :query page: The page number in case of a multi-page result set, default is 1
+   :param organizer: The ``slug`` field of a valid organizer
+   :param event: The ``slug`` field of the event to fetch
+   :param id: The ``id`` field of the exhibitor to fetch
+   :statuscode 200: no error
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer or event or exhibitor does not exist **or** you have no permission to view it.
+
+.. http:post:: /api/v1/organizers/(organizer)/events/(event)/exhibitors/(id)/vouchers/attach/
+
+   Attaches an **existing** voucher to an exhibitor. You need to send either the ``id`` **or** the ``code`` field of
+   the voucher.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      POST /api/v1/organizers/bigevents/events/sampleconf/exhibitors/1/vouchers/attach/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+     {
+       "id": 15
+     }
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      POST /api/v1/organizers/bigevents/events/sampleconf/exhibitors/1/vouchers/attach/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+     {
+       "code": "43K6LKM37FBVR2YG"
+     }
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: application/json
+
+      {}
+
+   :param organizer: The ``slug`` field of a valid organizer
+   :param event: The ``slug`` field of the event to use
+   :param id: The ``id`` field of the exhibitor to use
+   :statuscode 200: no error
+   :statuscode 400: Invalid data sent, e.g. voucher does not exist
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer or event or exhibitor does not exist **or** you have no permission to view it.
+
+.. http:post:: /api/v1/organizers/(organizer)/events/(event)/exhibitors/
+
+   Create a new exhibitor.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      POST /api/v1/organizers/bigevents/events/sampleconf/exhibitors/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+      Content-Type: application/json
+      Content-Length: 166
+
+      {
+        "name": "Aperture Science",
+        "internal_id": null,
+        "contact_name_parts": {
+            "_scheme": "salutation_title_given_family",
+            "family_name": "Johnson",
+            "given_name": "Cave",
+            "salutation": "",
+            "title": "Dr"
+        },
+        "contact_email": "johnson@as.example.org",
+        "booth": "A2",
+        "locale": "de",
+        "access_code": "VKHZ2FU8",
+        "allow_lead_scanning": true,
+        "allow_lead_access": true,
+        "allow_voucher_access": true,
+        "comment": ""
+      }
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 201 Created
+      Vary: Accept
+      Content-Type: application/json
+
+      {
+        "id": 1,
+        "name": "Aperture Science",
+        "internal_id": null,
+        "contact_name": "Dr Cave Johnson",
+        "contact_name_parts": {
+            "_scheme": "salutation_title_given_family",
+            "family_name": "Johnson",
+            "given_name": "Cave",
+            "salutation": "",
+            "title": "Dr"
+        },
+        "contact_email": "johnson@as.example.org",
+        "booth": "A2",
+        "locale": "de",
+        "access_code": "VKHZ2FU8",
+        "allow_lead_scanning": true,
+        "allow_lead_access": true,
+        "allow_voucher_access": true,
+        "comment": ""
+      }
+
+   :param organizer: The ``slug`` field of the organizer to create new exhibitor for
+   :param event: The ``slug`` field of the event to create new exhibitor for
+   :statuscode 201: no error
+   :statuscode 400: The exhibitor could not be created due to invalid submitted data.
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer/event does not exist **or** you have no permission to create exhibitors.
+
+
+.. http:patch:: /api/v1/organizers/(organizer)/events/(event)/exhibitors/(id)/
+
+   Update an exhibitor. You can also use ``PUT`` instead of ``PATCH``. With ``PUT``, you have to provide all fields of
+   the resource, other fields will be reset to default. With ``PATCH``, you only need to provide the fields that you
+   want to change.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      PATCH /api/v1/organizers/bigevents/events/sampleconf/digitalcontents/1/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+      Content-Type: application/json
+      Content-Length: 34
+
+      {
+        "internal_id": "ABC"
+      }
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: text/javascript
+
+      {
+        "id": 1,
+        "name": "Aperture Science",
+        "internal_id": "ABC",
+        "contact_name": "Dr Cave Johnson",
+        "contact_name_parts": {
+            "_scheme": "salutation_title_given_family",
+            "family_name": "Johnson",
+            "given_name": "Cave",
+            "salutation": "",
+            "title": "Dr"
+        },
+        "contact_email": "johnson@as.example.org",
+        "booth": "A2",
+        "locale": "de",
+        "access_code": "VKHZ2FU8",
+        "allow_lead_scanning": true,
+        "allow_lead_access": true,
+        "allow_voucher_access": true,
+        "comment": ""
+      }
+
+   :param organizer: The ``slug`` field of the organizer to modify
+   :param event: The ``slug`` field of the event to modify
+   :param id: The ``id`` field of the exhibitor to modify
+   :statuscode 200: no error
+   :statuscode 400: The exhibitor could not be modified due to invalid submitted data.
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer/event/exhibitor does not exist **or** you have no permission to change it.
+
+
+.. http:delete:: /api/v1/organizers/(organizer)/events/(event)/exhibitors/(id)/
+
+   Delete an exhibitor.
+
+   .. warning:: This deletes all lead scan data and removes all connections to vouchers (the vouchers are not deleted).
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      DELETE /api/v1/organizers/bigevents/events/sampleconf/exhibitors/1/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 204 No Content
+      Vary: Accept
+
+   :param organizer: The ``slug`` field of the organizer to modify
+   :param event: The ``slug`` field of the event to modify
+   :param id: The ``id`` field of the exhibitor to delete
+   :statuscode 204: no error
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer/event/exhibitor does not exist **or** you have no permission to change it
+
+
+App API
+-------
+
+The App API is used for communication between the pretixLEAD app and the pretix server.
+
+.. warning:: We consider this an internal API, it is not intended for external use. You may still use it, but
+             our :ref:`compatibility commitment <rest-compat>` does not apply.
+
+Authentication
+""""""""""""""
+
+Every exhibitor has an "access code", usually consisting of 8 alphanumeric uppercase characters.
+This access code is communicated to event exhibitors by the event organizers, so this is also what
+exhibitors should enter into a login screen.
+
+All API requests need to contain this access code as a header like this::
+
+    Authorization: Exhibitor ABCDE123
+
+Exhibitor profile
+"""""""""""""""""
+
+Upon login and in regular intervals after that, the API should fetch the exhibitors profile.
+This serves two purposes:
+
+* Checking if the authorization code is actually valid
+
+* Obtaining information that can be shown in the app
+
+The resource consists of the following fields:
+
+.. rst-class:: rest-resource-table
+
+===================================== ========================== =======================================================
+Field                                 Type                       Description
+===================================== ========================== =======================================================
+name                                  string                     Exhibitor name
+booth                                 string                     Booth number (or ``null``)
+event                                 object                     Object describing the event
+├ name                                multi-lingual string       Event name
+├ imprint_url                         string                     URL to legal notice page. If not ``null``, a button in the app should link to this page.
+├ privacy_url                         string                     URL to privacy notice page. If not ``null``, a button in the app should link to this page.
+├ help_url                            string                     URL to help page. If not ``null``, a button in the app should link to this page.
+├ logo_url                            string                     URL to event logo. If not ``null``, this logo may be shown in the app.
+├ slug                                string                     Event short form
+└ organizer                           string                     Organizer short form
+notes                                 boolean                    Specifies whether the exhibitor is allowed to take notes on leads
+tags                                  list of strings            List of tags the exhibitor can assign to their leads
+scan_types                            list of objects            Only used for a special case, fixed value that external API consumers should ignore
+===================================== ========================== =======================================================
+
+.. http:get:: /exhibitors/api/v1/profile
+
+   **Example request:**
+
+   .. sourcecode:: http
+
+    GET /exhibitors/api/v1/profile HTTP/1.1
+    Authorization: Exhibitor ABCDE123
+    Accept: application/json, text/javascript
+
+   **Example response:**
+
+   .. sourcecode:: http
+
+    HTTP/1.1 200 OK
+    Vary: Accept
+    Content-Type: application/json
+
+    {
+      "name": "Aperture Science",
+      "booth": "A2",
+      "event": {
+        "name": {"en": "Sample conference", "de": "Beispielkonferenz"},
+        "slug": "bigevents",
+        "imprint_url": null,
+        "privacy_url": null,
+        "help_url": null,
+        "logo_url": null,
+        "organizer": "sampleconf"
+      },
+      "notes": true,
+      "tags": ["foo", "bar"],
+      "scan_types": [
+        {
+          "key": "lead",
+          "label": "Lead Scanning"
+        }
+      ]
+    }
+
+   :statuscode 200: no error
+   :statuscode 401: Invalid authentication code
+
+Submitting a lead
+"""""""""""""""""
+
+After a ticket/badge is scanned, it should immediately be submitted to the server
+so the scan is stored and information about the person can be shown in the app. The same
+code can be submitted multiple times, so it's no problem to just submit it again after the
+exhibitor set a note or a rating (0-5) inside the app.
+
+On the request, you should set the following properties:
+
+* ``code`` with the scanned barcode
+* ``notes`` with the exhibitor's notes
+* ``scanned`` with the date and time of the actual scan (not the time of the upload)
+* ``scan_type`` set to ``lead`` statically
+* ``tags`` with the list of selected tags
+* ``rating`` with the rating assigned by the exhibitor
+* ``device_name`` with a user-specified name of the device used for scanning (max. 190 characters), or ``null``
+
+If you submit ``tags`` and ``rating`` to be ``null`` and ``notes`` to be ``""``, the server
+responds with the previously saved information and will not delete that information. If you
+supply other values, the information saved on the server will be overridden.
+
+The response will also contain ``tags``, ``rating``, and ``notes``. Additionally,
+it will include ``attendee`` with a list of ``fields`` that can be shown to the
+user. Each field has an internal ``id``, a human-readable ``label``, and a ``value`` (all strings).
+
+Note that the ``fields`` array can contain any number of dynamic keys!
+Depending on the exhibitors permission and event configuration this might be empty,
+or contain lots of details. The app should dynamically show these values (read-only)
+with the labels sent by the server.
+
+The request for this looks like this:
+
+.. http:post:: /exhibitors/api/v1/leads/
+
+   **Example request:**
+
+   .. sourcecode:: http
+
+    POST /exhibitors/api/v1/leads/ HTTP/1.1
+    Authorization: Exhibitor ABCDE123
+    Accept: application/json, text/javascript
+    Content-Type: application/json
+
+    {
+      "code": "qrcodecontent",
+      "notes": "Great customer, wants our newsletter",
+      "scanned": "2020-10-18T12:24:23.000+00:00",
+      "scan_type": "lead",
+      "tags": ["foo"],
+      "rating": 4,
+      "device_name": "DEV1"
+    }
+
+   **Example response:**
+
+   .. sourcecode:: http
+
+    HTTP/1.1 201 Created
+    Vary: Accept
+    Content-Type: application/json
+
+    {
+      "attendee": {
+        "fields": [
+          {
+            "id": "attendee_name",
+            "label": "Name",
+            "value": "Jon Doe",
+            "details": [
+              {"label": "Given name", "value": "John"},
+              {"label": "Family name", "value": "Doe"},
+            ]
+          },
+          {
+            "id": "attendee_email",
+            "label": "Email",
+            "value": "test@example.com",
+            "details": []
+          }
+         ]
+        },
+        "rating": 4,
+        "tags": ["foo"],
+        "notes": "Great customer, wants our newsletter"
+    }
+
+   :statuscode 200: No error, leads was not scanned for the first time
+   :statuscode 201: No error, leads was scanned for the first time
+   :statuscode 400: Invalid data submitted
+   :statuscode 401: Invalid authentication code
+
+You can also fetch existing leads (if you are authorized to do so):
+
+.. http:get:: /exhibitors/api/v1/leads/
+
+   **Example request:**
+
+   .. sourcecode:: http
+
+    GET /exhibitors/api/v1/leads/ HTTP/1.1
+    Authorization: Exhibitor ABCDE123
+    Accept: application/json, text/javascript
+
+   **Example response:**
+
+   .. sourcecode:: http
+
+    HTTP/1.1 200 OK
+    Vary: Accept
+    Content-Type: application/json
+
+    {
+      "count": 1,
+      "next": null,
+      "previous": null,
+      "results": [
+        {
+          "attendee": {
+            "fields": [
+              {
+                "id": "attendee_name",
+                "label": "Name",
+                "value": "Jon Doe",
+                "details": [
+                  {"label": "Given name", "value": "John"},
+                  {"label": "Family name", "value": "Doe"},
+                ]
+              },
+              {
+                "id": "attendee_email",
+                "label": "Email",
+                "value": "test@example.com",
+                "details": []
+              }
+           ]
+          },
+          "rating": 4,
+          "tags": ["foo"],
+          "notes": "Great customer, wants our newsletter"
+        }
+      ]
+    }
+
+   :statuscode 200: No error
+   :statuscode 401: Invalid authentication code
+   :statuscode 403: Not permitted to access bulk data

doc/plugins/imported_secrets.rst

@@ -0,0 +1,301 @@
+Secrets Import
+==============
+
+Usually, pretix generates ticket secrets (i.e. the QR code used for scanning) itself. You can read more about this
+process at :ref:`secret_generators`.
+
+With the "Secrets Import" plugin, you can upload your own list of secrets to be used instead. This is useful for
+integrating with third-party check-in systems.
+
+
+API Resource description
+-------------------------
+
+The secrets import plugin provides a HTTP API that allows you to create new secrets.
+
+The imported secret resource contains the following public fields:
+
+.. rst-class:: rest-resource-table
+
+===================================== ========================== =======================================================
+Field                                 Type                       Description
+===================================== ========================== =======================================================
+id                                    integer                    Internal ID of the secret
+secret                                string                     Actual string content of the secret (QR code content)
+used                                  boolean                    Whether the secret was already used for a ticket. If ``true``,
+                                                                 the secret can no longer be deleted. Secrets are never used
+                                                                 twice, even if an order is canceled or deleted.
+item                                  integer                    Internal ID of a product, or ``null``. If set, the secret
+                                                                 will only be used for tickets of this product.
+variation                             integer                    Internal ID of a product variation, or ``null``. If set, the secret
+                                                                 will only be used for tickets of this product variation.
+subevent                              integer                    Internal ID of an event series date, or ``null``. If set, the secret
+                                                                 will only be used for tickets of this event series date.
+===================================== ========================== =======================================================
+
+API Endpoints
+-------------
+
+.. http:get:: /api/v1/organizers/(organizer)/events/(event)/imported_secrets/
+
+   Returns a list of all secrets imported for an event.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      GET /api/v1/organizers/bigevents/events/sampleconf/imported_secrets/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: application/json
+
+      {
+        "count": 1,
+        "next": null,
+        "previous": null,
+        "results": [
+          {
+            "id": 1,
+            "secret": "foobar",
+            "used": false,
+            "item": null,
+            "variation": null,
+            "subevent": null
+          }
+        ]
+      }
+
+   :query page: The page number in case of a multi-page result set, default is 1
+   :param organizer: The ``slug`` field of a valid organizer
+   :param event: The ``slug`` field of the event to fetch
+   :statuscode 200: no error
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer or event does not exist **or** you have no permission to view it.
+
+.. http:get:: /api/v1/organizers/(organizer)/events/(event)/imported_secrets/(id)/
+
+   Returns information on one secret, identified by its ID.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      GET /api/v1/organizers/bigevents/events/sampleconf/imported_secrets/1/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: application/json
+
+      {
+        "id": 1,
+        "secret": "foobar",
+        "used": false,
+        "item": null,
+        "variation": null,
+        "subevent": null
+      }
+
+   :param organizer: The ``slug`` field of the organizer to fetch
+   :param event: The ``slug`` field of the event to fetch
+   :param id: The ``id`` field of the secret to fetch
+   :statuscode 200: no error
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer/event/secret does not exist **or** you have no permission to view it.
+
+.. http:post:: /api/v1/organizers/(organizer)/events/(event)/imported_secrets/
+
+   Create a new secret.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      POST /api/v1/organizers/bigevents/events/sampleconf/imported_secrets/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+      Content-Type: application/json
+      Content-Length: 166
+
+      {
+        "secret": "foobar",
+        "used": false,
+        "item": null,
+        "variation": null,
+        "subevent": null
+      }
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 201 Created
+      Vary: Accept
+      Content-Type: application/json
+
+      {
+        "id": 1,
+        "secret": "foobar",
+        "used": false,
+        "item": null,
+        "variation": null,
+        "subevent": null
+      }
+
+   :param organizer: The ``slug`` field of the organizer to a create new secret for
+   :param event: The ``slug`` field of the event to create a new secret for
+   :statuscode 201: no error
+   :statuscode 400: The secret could not be created due to invalid submitted data.
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer/event does not exist **or** you have no permission to create secrets.
+
+.. http:post:: /api/v1/organizers/(organizer)/events/(event)/imported_secrets/bulk_create/
+
+   Create new secrets in bulk (up to 500 per request). The request either succeeds or fails entirely.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      POST /api/v1/organizers/bigevents/events/sampleconf/imported_secrets/bulk_create/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+      Content-Type: application/json
+      Content-Length: 166
+
+      [
+        {
+          "secret": "foobar",
+          "used": false,
+          "item": null,
+          "variation": null,
+          "subevent": null
+        },
+        {
+          "secret": "baz",
+          "used": false,
+          "item": null,
+          "variation": null,
+          "subevent": null
+        }
+      ]
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: application/json
+
+      [
+        {
+          "id": 1,
+          "secret": "foobar",
+          "used": false,
+          "item": null,
+          "variation": null,
+          "subevent": null
+        },
+        {
+          "id": 2,
+          "secret": "baz",
+          "used": false,
+          "item": null,
+          "variation": null,
+          "subevent": null
+        }
+      ]
+
+   :param organizer: The ``slug`` field of the organizer to create new secrets for
+   :param event: The ``slug`` field of the event to create new secrets for
+   :statuscode 201: no error
+   :statuscode 400: The secrets could not be created due to invalid submitted data.
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer/event does not exist **or** you have no permission to create secrets.
+
+
+.. http:patch:: /api/v1/organizers/(organizer)/events/(event)/imported_secrets/(id)/
+
+   Update a secret. You can also use ``PUT`` instead of ``PATCH``. With ``PUT``, you have to provide all fields of
+   the resource, other fields will be reset to default. With ``PATCH``, you only need to provide the fields that you
+   want to change.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      PATCH /api/v1/organizers/bigevents/events/sampleconf/imported_secrets/1/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+      Content-Type: application/json
+      Content-Length: 34
+
+      {
+        "item": 2
+      }
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: text/javascript
+
+      {
+        "id": 1,
+        "secret": "foobar",
+        "used": false,
+        "item": 2,
+        "variation": null,
+        "subevent": null
+      }
+
+   :param organizer: The ``slug`` field of the organizer to modify
+   :param event: The ``slug`` field of the event to modify
+   :param id: The ``id`` field of the secret to modify
+   :statuscode 200: no error
+   :statuscode 400: The secret could not be modified due to invalid submitted data.
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer/event/secret does not exist **or** you have no permission to change it.
+
+
+.. http:delete:: /api/v1/organizers/(organizer)/events/(event)/imported_secrets/(id)/
+
+   Delete a secret. You can only delete secrets that have not yet been used.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      DELETE /api/v1/organizers/bigevents/events/sampleconf/imported_secrets/1/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 204 No Content
+      Vary: Accept
+
+   :param organizer: The ``slug`` field of the organizer to modify
+   :param event: The ``slug`` field of the event to modify
+   :param id: The ``id`` field of the secret to delete
+   :statuscode 204: no error
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer/event/secret does not exist **or** you have no permission to change it **or** the secret has already been used
+

doc/plugins/index.rst

@@ -1,3 +1,5 @@
+.. _`plugin-docs`:
+
 Plugin documentation
 ====================
 
@@ -10,11 +12,14 @@ If you want to **create** a plugin, please go to the
    :maxdepth: 2
 
    list
-   pretixdroid
    banktransfer
    ticketoutputpdf
    badges
    campaigns
    certificates
    digital
+   exhibitors
+   shipping
+   imported_secrets
    webinar
+   presale-saml

doc/plugins/list.rst

@@ -5,6 +5,6 @@ List of plugins
 ===============
 
 A detailed list of plugins that are available for pretix can be found on the
-`project website`_.
+`pretix Marketplace`_.
 
-.. _project website: https://pretix.eu/about/en/plugins
+.. _pretix Marketplace: https://marketplace.pretix.eu

doc/plugins/presale-saml.rst

@@ -0,0 +1,405 @@
+.. highlight:: ini
+.. spelling::
+
+   IdP
+   skIDentity
+   ePA
+   NPA
+
+Presale SAML Authentication
+===========================
+
+The Presale SAML Authentication plugin is an advanced plugin, which most event
+organizers will not need to use. However, for the select few  who do require
+strong customer authentication that cannot be covered by the built-in customer
+account functionality, this plugin allows pretix to connect to a SAML IdP and
+perform authentication and retrieval of user information.
+
+Usage of the plugin is governed by two separate sets of settings: The plugin
+installation, the Service Provider (SP) configuration and the event
+configuration.
+
+Plugin installation and initial configuration
+---------------------------------------------
+
+.. note:: If you are a customer of our hosted `pretix.eu`_ offering, you can
+          skip this section.
+
+The plugin is installed as any other plugin in the pretix ecosystem. As a
+pretix system administrator, please follow the instructions in the the
+:ref:`Administrator documentation <admindocs>`.
+
+Once installed, you will need to assess, if you want (or need) your pretix
+instance to be a single SP for all organizers and events or if every event
+organizer has to provide their own SP.
+
+Take the example of a university which runs pretix under an pretix Enterprise
+agreement. Since they only provide ticketing services to themselves (every
+organizer is still just a different department of the same university), a
+single SP should be enough.
+
+On the other hand, a reseller such as `pretix.eu`_ who services a multitude
+of clients would not work that way. Here, every organizer is a separate
+legal entity and as such will also need to provide their own SP configuration:
+Company A will expect their SP to reflect their company - and not a generalized
+"pretix SP".
+
+Once you have decided on the mode of operation, the :ref:`Configuration file
+<config>` needs to be extended to reflect your choice.
+
+Example::
+
+    [presale-saml]
+    level=global
+
+``level``
+    ``global`` to use only a single, system-wide SP, ``organizer`` for multiple
+    SPs, configured on the organizer-level. Defaults to ``organizer``.
+
+Service Provider configuration
+------------------------------
+
+Global Level
+^^^^^^^^^^^^
+
+.. note:: If you are a customer of our hosted `pretix.eu`_ offering, you can
+          skip this section and follow the instructions on the upcoming
+          Organizer Level settings.
+
+As a user with administrative privileges, please activate them by clicking the
+`Admin Mode` button in the top right hand corner.
+
+You should now see a new menu-item titled `SAML` appear.
+
+Organizer Level
+^^^^^^^^^^^^^^^
+
+Navigate to the organizer settings in the pretix backend. In the navigation
+bar, you will find a menu-item titled `SAML` if your user has the `Can
+change organizer settings` permission.
+
+
+.. note:: If you are a customer of our hosted `pretix.eu`_ offering, the menu
+          will only appear once one of our friendly customer service agents
+          has enabled the Presale SAML Authentication plugin for at least one
+          of your events. Feel free to get in touch with us!
+
+Setting up the SP
+^^^^^^^^^^^^^^^^^
+
+No matter where your SP configuration lives, you will be greeted by a very
+long list of fields of which almost all of them will need to be filled. Please
+don't be discouraged - most of the settings don't need to be decided by yourself
+and/or are already preset with a sensible default setting.
+
+If you are not sure what setting you should choose for any of the fields, you
+should reach out to your IdP operator as they can tell you exactly what the IdP
+expects and - more importantly - supports.
+
+``IdP Metadata URL``
+    Please provide the URL where your IdP outputs its metadata. For most IdPs,
+    this URL is static and the same for all SPs. If you are a member of the
+    DFN-AAI, you can find the meta-data for the `Test-, Basic- and
+    Advanced-Federation`_ on their website. Please do talk with your local
+    IdP operator though, as you might not even need to go through the DFN-AAI
+    and might just use your institutions local IdP which will also host their
+    metadata on a different URL.
+
+    The URL needs to be publicly accessible, as saving the settings form will
+    fail if the IdP metadata cannot be retrieved. pretix will also automatically
+    refresh the IdP metadata on a regular basis.
+
+``SP Entity Id``
+    By default, we recommend that you use the system-proposed metadata-URL as
+    the Entity Id of your SP. However, if so desired or required by your IdP,
+    you can also set any other, arbitrary URL as the SP Entity Id.
+
+``SP Name / SP Decription``
+    Most IdP will display the name and description of your SP to the users
+    during authentication. The description field can be used to explain to the
+    users how their data is being used.
+
+``SP X.509 Certificate / SP X.509 Private Key``
+    Your SP needs a certificate and a private key for said certificate. Please
+    coordinate with your IdP, if you are supposed to generate these yourself or
+    if they are provided to you.
+
+``SP X.509 New Certificate``
+    As certificates have an expiry date, they need to be renewed on a regular
+    basis. In order to facilitate the rollover from the expiring to the new
+    certificate, you can provide the new certificate already before the expiration
+    of the existing one. That way, the system will automatically use the correct
+    one. Once the old certificate has expired and is not used anymore at all,
+    you can move the new certificate into the slot of the normal certificate and
+    keep the new slot empty for your next renewal process.
+
+``Requested Attributes``
+    An IdP can hold a variety of attributes of an authenticating user. While
+    your IdP will dictate which of the available attributes your SP can consume
+    in theory, you will still need to define exactly which attributes the SP
+    should request.
+
+    The notation is a JSON list of objects with 5 attributes each:
+
+      * ``attributeValue``: Can be defaulted to ``[]``.
+      * ``friendlyName``: String used in the upcoming event-level settings to
+        retrieve the attributes data.
+      * ``isRequired``: Boolean indicating whether the IdP must enforce the
+        transmission of this attribute. In most cases, ``true`` is the best
+        choice.
+      * ``name``: String of the internal, technical name of the requested
+        attribute. Often starting with ``urn:mace:dir:attribute-def:``,
+        ``urn:oid:`` or ``http://``/``https://``.
+      * ``nameFormat``: String describing the type of ``name`` that has been
+        set in the previous section. Often starting with
+        ``urn:mace:shibboleth:1.0:`` or ``urn:oasis:names:tc:SAML:2.0:``.
+
+    Your IdP can provide you with a list of available attributes. See below
+    for a sample configuration in an academic context.
+
+    Note, that you can have multiple attributes with the same ``friendlyName``
+    but different ``name``s. This is often used in systems, where the same
+    information (for example a persons name) is saved in different fields -
+    for example because one institution is returning SAML 1.0 and other
+    institutions are returning SAML 2.0 style attributes. Typically, this only
+    occurs in mix environments like the DFN-AAI with a large number of
+    participants. If you are only using your own institutions IdP and not
+    authenticating anyone outside of your realm, this should not be a common
+    sight.
+
+``Encrypt/Sign/Require ...``
+    Does what is says on the box - please inquire with your IdP for the
+    necessary settings. Most settings can be turned on as they increase security,
+    however some IdPs might stumble over some of them.
+
+``Signature / Digest Algorithm``
+    Please chose appropriate algorithms, that both pretix/your SP and the IdP
+    can communicate with. A common source of issues when connecting to a
+    Shibboleth-based IdP is the Digest Algorithm: pretix does not support
+    ``http://www.w3.org/2009/xmlenc11#rsa-oaep`` and authentication will fail
+    if the IdP enforces this.
+
+``Technical/Support Contacts``
+    Those contacts are encoded into the SPs public meta data and might be
+    displayed to users having trouble authenticating. It is recommended to
+    provide a dedicated point of contact for technical issues, as those will
+    be the ones to change the configuration for the SP.
+
+Event / Authentication configuration
+------------------------------------
+
+Basic settings
+^^^^^^^^^^^^^^
+
+Once the plugin has been enabled for a pretix event using the Plugins-menu from
+the event's settings, a new *SAML* menu item will show up.
+
+On this page, the actual authentication can be configured.
+
+``Checkout Explanation``
+    Since most users probably won't be familiar with why they have to authenticate
+    to buy a ticket, you can provide them a small blurb here. Markdown is supported.
+
+``Attribute RegEx``
+    By default, any successful authentication with the IdP will allow the user to
+    proceed with their purchase. Should the allowed audience needed to be restricted
+    further, a set of regular Expressions can be used to do this.
+
+    An Attribute RegEx of ``{}`` will allow any authenticated user to pass.
+
+    A RegEx of ``{ "affiliation": "^(employee@pretix.eu|staff@pretix.eu)$" }`` will
+    only allow user to pass which have the ``affiliation`` attribute and whose
+    attribute either matches ``employee@pretix.eu`` or ``staff@pretix.eu``.
+
+    Please make sure that the attribute you are querying is also requested from the
+    IdP in the first place - for a quick check you can have a look at the top of
+    the page where all currently configured attributes are listed.
+
+``RegEx Fail Explanation``
+    Only used in conjunction with the above Attribute RegEx. Should the user not
+    pass the restrictions imposed by the regular expression, the user is shown
+    this error-message.
+
+    If you are - for example in an university context - restricting access to
+    students only, you might want to explain here that Employees are not allowed
+    to book tickets.
+
+``Ticket Secret SAML Attribute``
+    In very specific instances, it might be desirable that the ticket-secret is
+    not the randomly one generated by pretix but rather based on one of the
+    users attributes - for example their unique ID or access card number.
+
+    To achieve this, the name of a SAML-attribute can be specified here.
+
+    It is however necessary to note, that even with this setting in use,
+    ticket-secrets need to be unique. This is why when this setting is enabled,
+    the default, pretix-generated ticket-secret is prefixed with the attributes
+    value.
+
+    Example: A users ``cardid`` attribute has the value of ``01189998819991197253``.
+    The default random ticket secret would have been
+    ``yczygpw9877akz2xwdhtdyvdqwkv7npj``. The resulting new secret will now be
+    ``01189998819991197253_yczygpw9877akz2xwdhtdyvdqwkv7npj``.
+
+    That way, the ticket secret is still unique, but when checking into an event,
+    the user can easily be searched and found using their identifier.
+
+IdP-provided E-Mail addresses, names
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+By default, pretix will only authenticate the user and not process the received
+data any further.
+
+However, there are a few exceptions to this rule.
+
+There are a few `magic` attributes that pretix will use to automatically populate
+the corresponding fields within the checkout process **and lock them out from
+user editing**.
+
+  * ``givenName`` and ``sn``: If both of those attributes are present and pretix
+    is configured to collect the users name, these attributes' values are used
+    for the given and family name respectively.
+  * ``email``: If this attribute is present, the E-Mail-address of the users will
+    be set to the one transmitted through the attributes.
+
+The latter might pose a problem, if the IdP is transmitting an ``email`` attribute
+which does contain a system-level mail address which is only used as an internal
+identifier but not as a real mailbox. In this case, please consider setting the
+``friendlyName`` of the attribute to a different value than ``email`` or removing
+this field from the list of requested attributes altogether.
+
+Saving attributes to questions
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+By setting the ``internal identifier`` of a user-defined question to the same name
+as a SAML attribute, pretix will save the value of said attribute into the question.
+
+All the same as in the above section on E-Mail addresses, those fields become
+non-editable by the user.
+
+Please be aware that some specialty question types might not be compatible with
+the SAML attributes due to specific format requirements. If in doubt (or if the
+checkout fails/the information is not properly saved), try setting the question
+type to a simple type like "Text (one line)".
+
+Notes and configuration examples
+--------------------------------
+
+Requesting SAML 1.0 and 2.0 attributes from an academic IdP
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+This requests the ``eduPersonPrincipalName`` (also sometimes called EPPN),
+``email``, ``givenName`` and ``sn`` both in SAML 1.0 and SAML 2.0 attributes.
+
+.. sourcecode:: json
+
+    [
+        {
+            "attributeValue": [],
+            "friendlyName": "eduPersonPrincipalName",
+            "isRequired": true,
+            "name": "urn:mace:dir:attribute-def:eduPersonPrincipalName",
+            "nameFormat": "urn:mace:shibboleth:1.0:attributeNamespace:uri"
+        },
+        {
+            "attributeValue": [],
+            "friendlyName": "eduPersonPrincipalName",
+            "isRequired": true,
+            "name": "urn:oid:1.3.6.1.4.1.5923.1.1.1.6",
+            "nameFormat": "urn:oasis:names:tc:SAML:2.0:attrname-format:uri"
+        },
+        {
+            "attributeValue": [],
+            "friendlyName": "email",
+            "isRequired": true,
+            "name": "urn:mace:dir:attribute-def:mail",
+            "nameFormat": "urn:mace:shibboleth:1.0:attributeNamespace:uri"
+        },
+        {
+            "attributeValue": [],
+            "friendlyName": "email",
+            "isRequired": true,
+            "name": "urn:oid:0.9.2342.19200300.100.1.3",
+            "nameFormat": "urn:oasis:names:tc:SAML:2.0:attrname-format:uri"
+        },
+        {
+            "attributeValue": [],
+            "friendlyName": "givenName",
+            "isRequired": true,
+            "name": "urn:mace:dir:attribute-def:givenName",
+            "nameFormat": "urn:mace:shibboleth:1.0:attributeNamespace:uri"
+        },
+        {
+            "attributeValue": [],
+            "friendlyName": "givenName",
+            "isRequired": true,
+            "name": "urn:oid:2.5.4.42",
+            "nameFormat": "urn:oasis:names:tc:SAML:2.0:attrname-format:uri"
+        },
+        {
+            "attributeValue": [],
+            "friendlyName": "sn",
+            "isRequired": true,
+            "name": "urn:mace:dir:attribute-def:sn",
+            "nameFormat": "urn:mace:shibboleth:1.0:attributeNamespace:uri"
+        },
+        {
+            "attributeValue": [],
+            "friendlyName": "sn",
+            "isRequired": true,
+            "name": "urn:oid:2.5.4.4",
+            "nameFormat": "urn:oasis:names:tc:SAML:2.0:attrname-format:uri"
+        }
+    ]
+
+skIDentity IdP Metadata URL
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Since the IdP Metadata URL for `skIDentity`_ is not readily documented/visible
+in their backend, we document it here:
+``https://service.skidentity.de/fs/saml/metadata``
+
+Requesting skIDentity attributes for electronic identity cards
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+This requests the basic ``eIdentifier``, ``IDType``, ``IDIssuer``, and
+``NameID`` from the `skIDentity`_ SAML service, which are available for
+electronic ID cards such as the German ePA/NPA. (Other attributes such as
+the name and address are available at additional cost from the IdP).
+
+.. sourcecode:: json
+
+    [
+        {
+            "attributeValue": [],
+            "friendlyName": "eIdentifier",
+            "isRequired": true,
+            "name": "http://www.skidentity.de/att/eIdentifier",
+            "nameFormat": "urn:oasis:names:tc:SAML:2.0:attrname-format:uri"
+        },
+        {
+            "attributeValue": [],
+            "friendlyName": "IDType",
+            "isRequired": true,
+            "name": "http://www.skidentity.de/att/IDType",
+            "nameFormat": "urn:oasis:names:tc:SAML:2.0:attrname-format:uri"
+        },
+        {
+            "attributeValue": [],
+            "friendlyName": "IDIssuer",
+            "isRequired": true,
+            "name": "http://www.skidentity.de/att/IDIssuer",
+            "nameFormat": "urn:oasis:names:tc:SAML:2.0:attrname-format:uri"
+        },
+        {
+            "attributeValue": [],
+            "friendlyName": "NameID",
+            "isRequired": true,
+            "name": "http://www.skidentity.de/att/NameID",
+            "nameFormat": "urn:oasis:names:tc:SAML:2.0:attrname-format:uri"
+        }
+    ]
+
+.. _pretix.eu: https://pretix.eu
+.. _Test-, Basic- and Advanced-Federation: https://doku.tid.dfn.de/en:metadata
+.. _skIDentity: https://www.skidentity.de/

doc/plugins/pretixdroid.rst

@@ -1,368 +0,0 @@
-pretixdroid HTTP API
-====================
-
-The pretixdroid plugin provides a HTTP API that the `pretixdroid Android app`_
-uses to communicate with the pretix server.
-
-.. warning:: This API is **DEPRECATED** and will probably go away soon. It is used **only** to serve the pretixdroid
-             Android app. There are no backwards compatibility guarantees on this API. We will not add features that
-             are not required for the  Android App. There is a general-purpose :ref:`rest-api` that provides all
-             features that you need to check in.
-
-.. versionchanged:: 1.12
-
-   Support for check-in-time questions has been added. The new API features are fully backwards-compatible and
-   negotiated live, so clients which do not need this feature can ignore the change. For this reason, the API version
-   has not been increased and is still set to 3.
-
-.. versionchanged:: 1.13
-
-   Support for checking in unpaid tickets has been added.
-
-
-.. http:post:: /pretixdroid/api/(organizer)/(event)/redeem/
-
-   Redeems a ticket, i.e. checks the user in.
-
-   **Example request**:
-
-   .. sourcecode:: http
-
-      POST /pretixdroid/api/demoorga/democon/redeem/?key=ABCDEF HTTP/1.1
-      Host: demo.pretix.eu
-      Accept: application/json, text/javascript
-      Content-Type: application/x-www-form-urlencoded
-
-      secret=az9u4mymhqktrbupmwkvv6xmgds5dk3&questions_supported=true
-
-   You **must** set the parameter secret.
-
-   You **must** set the parameter ``questions_supported`` to ``true`` **if** you support asking questions
-   back to the app operator. You **must not** set it if you do not support this feature. In that case, questions
-   will just be ignored.
-
-   You **may** set the additional parameter ``datetime`` in the body containing an ISO8601-encoded
-   datetime of the entry attempt. If you don"t, the current date and time will be used.
-
-   You **may** set the additional parameter ``force`` to indicate that the request should be logged
-   regardless of previous check-ins for the same ticket. This might be useful if you made the entry decision offline.
-   Questions will also always be ignored in this case (i.e. supplied answers will be saved, but no error will be
-   thrown if they are missing or invalid).
-
-   You **may** set the additional parameter ``nonce`` with a globally unique random value to identify this
-   check-in. This is meant to be used to prevent duplicate check-ins when you are just retrying after a connection
-   failure.
-
-   You **may** set the additional parameter ``ignore_unpaid`` to indicate that the check-in should be performed even
-   if the order is in pending state.
-
-   If questions are supported and required, you will receive a dictionary ``questions`` containing details on the
-   particular questions to ask. To answer them, just re-send your redemption request with additional parameters of
-   the form ``answer_<question>=<answer>``, e.g. ``answer_12=24``.
-
-   **Example successful response**:
-
-   .. sourcecode:: http
-
-      HTTP/1.1 200 OK
-      Content-Type: text/json
-
-      {
-        "status": "ok"
-        "version": 3,
-        "data": {
-          "secret": "az9u4mymhqktrbupmwkvv6xmgds5dk3",
-          "order": "ABCDE",
-          "item": "Standard ticket",
-          "item_id": 1,
-          "variation": null,
-          "variation_id": null,
-          "attendee_name": "Peter Higgs",
-          "attention": false,
-          "redeemed": true,
-          "checkin_allowed": true,
-          "addons_text": "Parking spot",
-          "paid": true
-        }
-      }
-
-   **Example response with required questions**:
-
-   .. sourcecode:: http
-
-      HTTP/1.1 200 OK
-      Content-Type: text/json
-
-      {
-        "status": "incomplete"
-        "version": 3
-        "data": {
-          "secret": "az9u4mymhqktrbupmwkvv6xmgds5dk3",
-          "order": "ABCDE",
-          "item": "Standard ticket",
-          "item_id": 1,
-          "variation": null,
-          "variation_id": null,
-          "attendee_name": "Peter Higgs",
-          "attention": false,
-          "redeemed": true,
-          "checkin_allowed": true,
-          "addons_text": "Parking spot",
-          "paid": true
-        },
-        "questions": [
-          {
-            "id": 12,
-            "type": "C",
-            "question": "Choose a shirt size",
-            "required": true,
-            "position": 2,
-            "items": [1],
-            "options": [
-              {
-                "id": 24,
-                "answer": "M"
-              },
-              {
-                "id": 25,
-                "answer": "L"
-              }
-            ]
-          }
-        ]
-      }
-
-   **Example error response with data**:
-
-   .. sourcecode:: http
-
-      HTTP/1.1 200 OK
-      Content-Type: text/json
-
-      {
-        "status": "error",
-        "reason": "already_redeemed",
-        "version": 3,
-        "data": {
-          "secret": "az9u4mymhqktrbupmwkvv6xmgds5dk3",
-          "order": "ABCDE",
-          "item": "Standard ticket",
-          "item_id": 1,
-          "variation": null,
-          "variation_id": null,
-          "attendee_name": "Peter Higgs",
-          "attention": false,
-          "redeemed": true,
-          "checkin_allowed": true,
-          "addons_text": "Parking spot",
-          "paid": true
-        }
-      }
-
-   **Example error response without data**:
-
-   .. sourcecode:: http
-
-      HTTP/1.1 200 OK
-      Content-Type: text/json
-
-      {
-        "status": "error",
-        "reason": "unkown_ticket",
-        "version": 3
-      }
-
-   Possible error reasons:
-
-   * ``unpaid`` - Ticket is not paid for or has been refunded
-   * ``already_redeemed`` - Ticket already has been redeemed
-   * ``product`` - Tickets with this product may not be scanned at this device
-   * ``unknown_ticket`` - Secret does not match a ticket in the database
-
-   :query key: Secret API key
-   :statuscode 200: Valid request
-   :statuscode 404: Unknown organizer or event
-   :statuscode 403: Invalid authorization key
-
-.. http:get:: /pretixdroid/api/(organizer)/(event)/search/
-
-   Searches for a ticket.
-   At most 25 results will be returned. **Queries with less than 4 characters will always return an empty result set.**
-
-   **Example request**:
-
-   .. sourcecode:: http
-
-      GET /pretixdroid/api/demoorga/democon/search/?key=ABCDEF&query=Peter HTTP/1.1
-      Host: demo.pretix.eu
-      Accept: application/json, text/javascript
-
-   **Example response**:
-
-   .. sourcecode:: http
-
-      HTTP/1.1 200 OK
-      Content-Type: text/json
-
-      {
-        "results": [
-          {
-            "secret": "az9u4mymhqktrbupmwkvv6xmgds5dk3",
-            "order": "ABCE6",
-            "item": "Standard ticket",
-            "variation": null,
-            "attendee_name": "Peter Higgs",
-            "redeemed": false,
-            "attention": false,
-            "checkin_allowed": true,
-            "addons_text": "Parking spot",
-            "paid": true
-          },
-          ...
-        ],
-        "version": 3
-      }
-
-   :query query: Search query
-   :query key: Secret API key
-   :statuscode 200: Valid request
-   :statuscode 404: Unknown organizer or event
-   :statuscode 403: Invalid authorization key
-
-.. http:get:: /pretixdroid/api/(organizer)/(event)/download/
-
-   Download data for all tickets.
-
-   **Example request**:
-
-   .. sourcecode:: http
-
-      GET /pretixdroid/api/demoorga/democon/download/?key=ABCDEF HTTP/1.1
-      Host: demo.pretix.eu
-      Accept: application/json, text/javascript
-
-   **Example response**:
-
-   .. sourcecode:: http
-
-      HTTP/1.1 200 OK
-      Content-Type: text/json
-
-      {
-        "version": 3,
-        "results": [
-          {
-            "secret": "az9u4mymhqktrbupmwkvv6xmgds5dk3",
-            "order": "ABCE6",
-            "item": "Standard ticket",
-            "variation": null,
-            "attendee_name": "Peter Higgs",
-            "redeemed": false,
-            "attention": false,
-            "checkin_allowed": true,
-            "paid": true
-          },
-          ...
-        ],
-        "questions": [
-          {
-            "id": 12,
-            "type": "C",
-            "question": "Choose a shirt size",
-            "required": true,
-            "position": 2,
-            "items": [1],
-            "options": [
-              {
-                "id": 24,
-                "answer": "M"
-              },
-              {
-                "id": 25,
-                "answer": "L"
-              }
-            ]
-          }
-        ]
-      }
-
-   :query key: Secret API key
-   :statuscode 200: Valid request
-   :statuscode 404: Unknown organizer or event
-   :statuscode 403: Invalid authorization key
-
-.. http:get:: /pretixdroid/api/(organizer)/(event)/status/
-
-   Returns status information, such as the total number of tickets and the
-   number of performed check-ins.
-
-   **Example request**:
-
-   .. sourcecode:: http
-
-      GET /pretixdroid/api/demoorga/democon/status/?key=ABCDEF HTTP/1.1
-      Host: demo.pretix.eu
-      Accept: application/json, text/javascript
-
-   **Example response**:
-
-   .. sourcecode:: http
-
-      HTTP/1.1 200 OK
-      Content-Type: text/json
-
-      {
-        "checkins": 17,
-        "total": 42,
-        "version": 3,
-        "event": {
-          "name": "Demo Conference",
-          "slug": "democon",
-          "date_from": "2016-12-27T17:00:00Z",
-          "date_to": "2016-12-30T18:00:00Z",
-          "timezone": "UTC",
-          "url": "https://demo.pretix.eu/demoorga/democon/",
-          "organizer": {
-            "name": "Demo Organizer",
-            "slug": "demoorga"
-          },
-        },
-        "items": [
-          {
-            "name": "T-Shirt",
-            "id": 1,
-            "checkins": 1,
-            "admission": False,
-            "total": 1,
-            "variations": [
-              {
-                "name": "Red",
-                "id": 1,
-                "checkins": 1,
-                "total": 12
-              },
-              {
-               "name": "Blue",
-                "id": 2,
-                "checkins": 4,
-                "total": 8
-              }
-            ]
-          },
-          {
-            "name": "Ticket",
-            "id": 2,
-            "checkins": 15,
-            "admission": True,
-            "total": 22,
-            "variations": []
-          }
-        ]
-      }
-
-   :query key: Secret API key
-   :statuscode 200: Valid request
-   :statuscode 404: Unknown organizer or event
-   :statuscode 403: Invalid authorization key
-
-.. _pretixdroid Android app: https://github.com/pretix/pretixdroid

doc/plugins/shipping.rst

@@ -0,0 +1,235 @@
+Shipping
+========
+
+The shipping plugin provides a HTTP API that exposes the various layouts used to generate PDF badges.
+
+Shipping address resource
+-------------------------
+
+The shipping address resource contains the following public fields:
+
+.. rst-class:: rest-resource-table
+
+===================================== ========================== =======================================================
+Field                                 Type                       Description
+===================================== ========================== =======================================================
+company                               string                     Customer company name
+name                                  string                     Customer name
+street                                string                     Customer street
+zipcode                               string                     Customer ZIP code
+city                                  string                     Customer city
+country                               string                     Customer country code
+state                                 string                     Customer state (ISO 3166-2 code). Only supported in
+                                                                 AU, BR, CA, CN, MY, MX, and US.
+gift                                  boolean                    Request by customer to not disclose prices in the shipping
+===================================== ========================== =======================================================
+
+Shipping status resource
+------------------------
+
+The shipping status resource contains the following public fields:
+
+.. rst-class:: rest-resource-table
+
+===================================== ========================== =======================================================
+Field                                 Type                       Description
+===================================== ========================== =======================================================
+method                                integer                    Internal ID of shipping method
+status                                string                     Status, one of ``"new"`` or ``"shipped"``
+method_type                           string                     Method type, one of ``"ship"``, ``"online"``, or ``"collect"``
+===================================== ========================== =======================================================
+
+Print job resource
+------------------
+
+The print job resource contains the following public fields:
+
+.. rst-class:: rest-resource-table
+
+===================================== ========================== =======================================================
+Field                                 Type                       Description
+===================================== ========================== =======================================================
+code                                  string                     Order code of the ticket order
+event                                 string                     Event slug
+status                                string                     Status, one of ``"new"`` or ``"shipped"``
+method                                string                     Method type, one of ``"ship"``, ``"online"``, or ``"collect"``
+===================================== ========================== =======================================================
+
+Endpoints
+---------
+
+.. http:get:: /api/v1/organizers/(organizer)/events/(event)/orders/(code)/shippingaddress/
+
+   Returns the shipping address of an order
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      GET /api/v1/organizers/bigevents/events/democon/orders/ABC12/shippingaddress/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: text/javascript
+
+      {
+        "company": "ACME Corp",
+        "name": "John Doe",
+        "street": "Sesame Street 12\nAp. 5",
+        "zipcode": "12345",
+        "city": "Berlin",
+        "country": "DE",
+        "state": "",
+        "gift": false
+      }
+
+   :param organizer: The ``slug`` field of a valid organizer
+   :param event: The ``slug`` field of a valid event
+   :param order: The ``code`` field of a valid order
+   :statuscode 200: no error
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer does not exist **or** you have no permission to view it.
+   :statuscode 404: The order does not exist or no shipping address is attached.
+
+
+.. http:get:: /api/v1/organizers/(organizer)/events/(event)/orders/(code)/shippingaddress/
+
+   Returns the shipping status of an order
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      GET /api/v1/organizers/bigevents/events/democon/orders/ABC12/shippingstatus/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: text/javascript
+
+      {
+        "method": 23,
+        "method_type": "ship",
+        "status": "new"
+      }
+
+   :param organizer: The ``slug`` field of a valid organizer
+   :param event: The ``slug`` field of a valid event
+   :param order: The ``code`` field of a valid order
+   :statuscode 200: no error
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer does not exist **or** you have no permission to view it.
+   :statuscode 404: The order does not exist or no shipping address is attached.
+
+.. http:get:: /api/v1/organizers/(organizer)/printjobs/
+
+   Returns a list of ticket orders, only useful with some query filters
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      GET /api/v1/organizers/bigevents/printjobs/?method=ship&status=new HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: text/javascript
+
+      {
+        "count": 1,
+        "next": null,
+        "previous": null,
+        "results": [
+          {
+            "event": "democon",
+            "order": "ABC12",
+            "method": "ship",
+            "status": "new"
+          }
+        ]
+      }
+
+   :query string method: Filter by response field ``method`` (can be passed multiple times)
+   :query string status: Filter by response field ``status``
+   :query string event: Filter by response field ``event``
+   :param organizer: The ``slug`` field of a valid organizer
+   :param event: The ``slug`` field of a valid event
+   :statuscode 200: no error
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer does not exist **or** you have no permission to view it.
+
+.. http:get:: /api/v1/organizers/(organizer)/printjobs/poll/
+
+   Returns the PDF file for the next job to print.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      GET /api/v1/organizers/bigevents/printjobs/poll/?method=ship&status=new HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: application/pdf
+      X-Pretix-Order-Code: ABC12
+
+      ...
+
+   :query string method: Filter by response field ``method`` (can be passed multiple times)
+   :query string status: Filter by response field ``status``
+   :query string event: Filter by response field ``event``
+   :param organizer: The ``slug`` field of a valid organizer
+   :param event: The ``slug`` field of a valid event
+   :statuscode 200: no error
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer does not exist **or** you have no permission to view it.
+
+.. http:post:: /api/v1/organizers/(organizer)/printjobs/(order)/ack/
+
+   Change an order's status to "shipped".
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      POST /api/v1/organizers/bigevents/printjobs/ABC12/ack/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 204 No Content
+      Vary: Accept
+
+   :param organizer: The ``slug`` field of a valid organizer
+   :param event: The ``slug`` field of a valid event
+   :param order: The ``code`` field of a valid order
+   :statuscode 200: no error
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer does not exist **or** you have no permission to view it.
+   :statuscode 404: The order does not exist.

doc/requirements.txt

@@ -1,5 +1,6 @@
 -e ../src/
 sphinx==2.3.*
+jinja2==3.0.*
 sphinx-rtd-theme
 sphinxcontrib-httpdomain
 sphinxcontrib-images

doc/spelling_wordlist.txt

@@ -103,6 +103,7 @@ prepending
 preprocessor
 presale
 pretix
+pretixLEAD
 pretixSCAN
 pretixdroid
 pretixPOS

doc/user/events/email.rst

@@ -203,4 +203,4 @@ Then, please contact support@pretix.eu and we will enable DKIM for your domain o
 
 
 .. _Sender Policy Framework: https://en.wikipedia.org/wiki/Sender_Policy_Framework
-.. _SPF specification: http://www.openspf.org/SPF_Record_Syntax
+.. _SPF specification: http://www.open-spf.org/SPF_Record_Syntax

doc/user/events/guides/groups.rst

@@ -1,20 +1,44 @@
 Use case: Group discounts
 -------------------------
 
-Often times, you want to give discounts for whole groups attending your event. pretix can't automatically discount based on volume, but there's still some ways you can set up group tickets.
+Often times, you want to give discounts for whole groups attending your event.
 
-Flexible group sizes
+Automatic discounts
+"""""""""""""""""""
+
+pretix can automatically grant discounts if a certain condition is met, such as a specific group size. To set this up,
+head to **Products**, **Discounts** in the event navigation and **Create a new discount**. You can choose a name so you
+can later find this again. You can also optionally restrict the discount to a specific time frame or a specific sales
+channel.
+
+Next, either select **Apply to all products** or create a selection of products that are eligible for the discount.
+
+For a **percentual group discount** similar to "if you buy at least 5 tickets, you get 20 percent off", set
+**Minimum number of matching products** to "5" and **Percentual discount on matching products** to "20.00".
+
+For a **buy-X-get-Y discount**, e.g. "if you buy 5 tickets, you get one free", set
+**Minimum number of matching products** to "5", **Percentual discount on matching products** to "100.00", and
+**Apply discount only to this number of matching products** to "1".
+
+Fixed group packages
 """"""""""""""""""""
 
-If you want to give out discounted tickets to groups starting at a given size, but still billed per person, you can do so by creating a special **Group ticket** at the per-person price and set the **Minimum amount per order** option of the ticket to the minimal group size.
+If you want to sell group tickets in fixed sizes, e.g. a table of eight at your gala dinner, you can use product bundles.
+Assuming you already set up a ticket for admission of single persons, you then set up a second product **Table (8 persons)**
+with a discounted full price. Then, head to the **Bundled products** tab of that product and add one bundle configuration
+to include the single admission product **eight times**. Next, create an unlimited quota mapped to the new product.
+
+This way, the purchase of a table will automatically create eight tickets, leading to a correct calculation of your total
+quota and, as expected, eight persons on your check-in list. You can even ask for the individual names of the persons
+during checkout.
+
+Minimum order amount
+""""""""""""""""""""
+
+If you want to promote discounted group tickets in your price list, you can also do so by creating a special
+**Group ticket** at the reduced per-person price and set the **Minimum amount per order** option of the ticket to the minimal
+group size.
 
 For more complex use cases, you can also use add-on products that can be chosen multiple times.
 
 This way, your ticket can be bought an arbitrary number of times – but no less than the given minimal amount per order.
-
-Fixed group sizes
-"""""""""""""""""
-
-If you want to sell group tickets in fixed sizes, e.g. a table of eight at your gala dinner, you can use product bundles. Assuming you already set up a ticket for admission of single persons, you then set up a second product **Table (8 persons)** with a discounted full price. Then, head to the **Bundled products** tab of that product and add one bundle configuration to include the single admission product **eight times**. Next, create an unlimited quota mapped to the new product.
-
-This way, the purchase of a table will automatically create eight tickets, leading to a correct calculation of your total quota and, as expected, eight persons on your check-in list. You can even ask for the individual names of the persons during checkout.

doc/user/events/ticket_secrets.rst

@@ -1,3 +1,5 @@
+.. _secret_generators:
+
 Ticket secret generators
 ========================
 

doc/user/events/widget.rst

@@ -253,18 +253,21 @@ If you want, you can suppress us loading the widget and/or modify the user data
 
 If you then later want to trigger loading the widgets, just call ``window.PretixWidget.buildWidgets()``.
 
-Waiting for the widget to load
-------------------------------
+Waiting for the widget to load or close
+---------------------------------------
 
-If you want to run custom JavaScript once the widget is fully loaded, you can register a callback function. Note that
-this function might be run multiple times, for example if you have multiple widgets on a page or if the user switches
-e.g. from an event list to an event detail view::
+If you want to run custom JavaScript once the widget is fully loaded or when it is closed, you can register callback
+functions. Note that these function might be run multiple times, for example if you have multiple widgets on a page
+or if the user switches e.g. from an event list to an event detail view::
 
     <script type="text/javascript">
     window.pretixWidgetCallback = function () {
         window.PretixWidget.addLoadListener(function () {
             console.log("Widget has loaded!");
         });
+        window.PretixWidget.addCloseListener(function () {
+            console.log("Widget has been closed!");
+        });
     }
     </script>
 
@@ -309,6 +312,10 @@ Currently, the following attributes are understood by pretix itself:
   always be modified. Note that this is not a security feature and can easily be overridden by users, so do not rely
   on this for authentication.
 
+* If ``data-consent="…"`` is given, the cookie consent mechanism will be initialized with consent for the given cookie
+  providers. All other providers will be disabled, no consent dialog will be shown. This is useful if you already
+  asked the user for consent and don't want them to be asked again. Example: ``data-consent="facebook,google_analytics"``
+
 Any configured pretix plugins might understand more data fields. For example, if the appropriate plugins on pretix
 Hosted or pretix Enterprise are active, you can pass the following fields:
 

doc/user/glossary.rst

@@ -84,7 +84,9 @@ going to develop around pretix, for example connect to pretix through our API, y
      - A voucher is a code that can be used for multiple purposes: To grant a discount to specific customers, to only
        show certain products to certain customers, or to keep a seat open for someone specific even though you are
        sold out. If a voucher is used to apply a discount, the price of the purchased product is reduced by the
-       discounted amount. Vouchers are connected to a specific event.
+   * - | |:gb:| **(Automatic) Discount**
+       | |:de:| (Automatischer) Rabatt
+     - Discounts can be used to automatically provide discounts to customers if their cart satisfies a certain condition.
    * - | |:gb:| **Gift card**
        | |:de:| Wertgutschein
      - A :ref:`gift card <giftcards>` is a coupon representing an exact amount of money that can be used for purchases

src/MANIFEST.in

@@ -13,6 +13,7 @@ recursive-include pretix/plugins/banktransfer/static *
 recursive-include pretix/plugins/manualpayment/templates *
 recursive-include pretix/plugins/manualpayment/static *
 recursive-include pretix/plugins/paypal/templates *
+recursive-include pretix/plugins/paypal/static *
 recursive-include pretix/plugins/pretixdroid/templates *
 recursive-include pretix/plugins/pretixdroid/static *
 recursive-include pretix/plugins/sendmail/templates *

src/pretix/__init__.py

@@ -19,4 +19,4 @@
 # You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
 # <https://www.gnu.org/licenses/>.
 #
-__version__ = "4.5.0"
+__version__ = "4.11.0"

src/pretix/api/auth/devicesecurity.py

@@ -45,6 +45,7 @@ class PretixScanSecurityProfile(AllowListSecurityProfile):
     allowlist = (
         ('GET', 'api-v1:version'),
         ('GET', 'api-v1:device.eventselection'),
+        ('GET', 'api-v1:idempotency.query'),
         ('POST', 'api-v1:device.update'),
         ('POST', 'api-v1:device.revoke'),
         ('POST', 'api-v1:device.roll'),
@@ -76,6 +77,7 @@ class PretixScanNoSyncNoSearchSecurityProfile(AllowListSecurityProfile):
     allowlist = (
         ('GET', 'api-v1:version'),
         ('GET', 'api-v1:device.eventselection'),
+        ('GET', 'api-v1:idempotency.query'),
         ('POST', 'api-v1:device.update'),
         ('POST', 'api-v1:device.revoke'),
         ('POST', 'api-v1:device.roll'),
@@ -105,6 +107,7 @@ class PretixScanNoSyncSecurityProfile(AllowListSecurityProfile):
     allowlist = (
         ('GET', 'api-v1:version'),
         ('GET', 'api-v1:device.eventselection'),
+        ('GET', 'api-v1:idempotency.query'),
         ('POST', 'api-v1:device.update'),
         ('POST', 'api-v1:device.revoke'),
         ('POST', 'api-v1:device.roll'),
@@ -135,6 +138,7 @@ class PretixPosSecurityProfile(AllowListSecurityProfile):
     allowlist = (
         ('GET', 'api-v1:version'),
         ('GET', 'api-v1:device.eventselection'),
+        ('GET', 'api-v1:idempotency.query'),
         ('POST', 'api-v1:device.update'),
         ('POST', 'api-v1:device.revoke'),
         ('POST', 'api-v1:device.roll'),
@@ -151,6 +155,8 @@ class PretixPosSecurityProfile(AllowListSecurityProfile):
         ('GET', 'api-v1:ticketlayoutitem-list'),
         ('GET', 'api-v1:badgelayout-list'),
         ('GET', 'api-v1:badgeitem-list'),
+        ('GET', 'api-v1:voucher-list'),
+        ('GET', 'api-v1:voucher-detail'),
         ('GET', 'api-v1:order-list'),
         ('POST', 'api-v1:order-list'),
         ('GET', 'api-v1:order-detail'),
@@ -167,6 +173,8 @@ class PretixPosSecurityProfile(AllowListSecurityProfile):
         ('GET', 'api-v1:checkinlist-list'),
         ('POST', 'api-v1:checkinlistpos-redeem'),
         ('POST', 'plugins:pretix_posbackend:order.posprintlog'),
+        ('POST', 'plugins:pretix_posbackend:order.poslock'),
+        ('DELETE', 'plugins:pretix_posbackend:order.poslock'),
         ('DELETE', 'api-v1:cartposition-detail'),
         ('GET', 'api-v1:giftcard-list'),
         ('POST', 'api-v1:giftcard-transact'),
@@ -174,8 +182,11 @@ class PretixPosSecurityProfile(AllowListSecurityProfile):
         ('POST', 'plugins:pretix_posbackend:posreceipt-list'),
         ('POST', 'plugins:pretix_posbackend:posclosing-list'),
         ('POST', 'plugins:pretix_posbackend:posdebugdump-list'),
+        ('POST', 'plugins:pretix_posbackend:posdebuglogentry-list'),
+        ('POST', 'plugins:pretix_posbackend:posdebuglogentry-bulk-create'),
         ('GET', 'plugins:pretix_posbackend:poscashier-list'),
         ('POST', 'plugins:pretix_posbackend:stripeterminal.token'),
+        ('PUT', 'plugins:pretix_posbackend:file.upload'),
         ('GET', 'api-v1:revokedsecrets-list'),
         ('GET', 'api-v1:event.settings'),
         ('GET', 'plugins:pretix_seating:event.event'),

src/pretix/api/serializers/cart.py

@@ -23,6 +23,7 @@ import os
 from datetime import timedelta
 
 from django.core.files import File
+from django.db.models import Q
 from django.utils.crypto import get_random_string
 from django.utils.timezone import now
 from django.utils.translation import gettext_lazy
@@ -33,13 +34,19 @@ from pretix.api.serializers.i18n import I18nAwareModelSerializer
 from pretix.api.serializers.order import (
     AnswerCreateSerializer, AnswerSerializer, InlineSeatSerializer,
 )
-from pretix.base.models import Quota, Seat
+from pretix.base.models import Quota, Seat, Voucher
 from pretix.base.models.orders import CartPosition
 
 
+class TaxIncludedField(serializers.Field):
+    def to_representation(self, instance: CartPosition):
+        return not instance.custom_price_input_is_net
+
+
 class CartPositionSerializer(I18nAwareModelSerializer):
     answers = AnswerSerializer(many=True)
     seat = InlineSeatSerializer()
+    includes_tax = TaxIncludedField(source='*')
 
     class Meta:
         model = CartPosition
@@ -54,11 +61,13 @@ class CartPositionCreateSerializer(I18nAwareModelSerializer):
     attendee_name = serializers.CharField(required=False, allow_null=True)
     seat = serializers.CharField(required=False, allow_null=True)
     sales_channel = serializers.CharField(required=False, default='sales_channel')
+    includes_tax = serializers.BooleanField(required=False, allow_null=True)
+    voucher = serializers.CharField(required=False, allow_null=True)
 
     class Meta:
         model = CartPosition
         fields = ('cart_id', 'item', 'variation', 'price', 'attendee_name', 'attendee_name_parts', 'attendee_email',
-                  'subevent', 'expires', 'includes_tax', 'answers', 'seat', 'sales_channel')
+                  'subevent', 'expires', 'includes_tax', 'answers', 'seat', 'sales_channel', 'voucher')
 
     def create(self, validated_data):
         answers_data = validated_data.pop('answers')
@@ -118,15 +127,53 @@ class CartPositionCreateSerializer(I18nAwareModelSerializer):
                 raise ValidationError('The specified seat ID is not unique.')
             else:
                 validated_data['seat'] = seat
-                if not seat.is_available(
-                    sales_channel=validated_data.get('sales_channel', 'web'),
-                    distance_ignore_cart_id=validated_data['cart_id'],
-                ):
-                    raise ValidationError(gettext_lazy('The selected seat "{seat}" is not available.').format(seat=seat.name))
         elif seated:
             raise ValidationError('The specified product requires to choose a seat.')
 
+        if validated_data.get('voucher'):
+            try:
+                voucher = self.context['event'].vouchers.get(code__iexact=validated_data.get('voucher'))
+            except Voucher.DoesNotExist:
+                raise ValidationError('The specified voucher does not exist.')
+
+            if voucher and not voucher.applies_to(validated_data.get('item'), validated_data.get('variation')):
+                raise ValidationError('The specified voucher is not valid for the given item and variation.')
+
+            if voucher and voucher.seat and voucher.seat != validated_data.get('seat'):
+                raise ValidationError('The specified voucher is not valid for this seat.')
+
+            if voucher and voucher.subevent_id and (not validated_data.get('subevent') or voucher.subevent_id != validated_data['subevent'].pk):
+                raise ValidationError('The specified voucher is not valid for this subevent.')
+
+            if voucher.valid_until is not None and voucher.valid_until < now():
+                raise ValidationError('The specified voucher is expired.')
+
+            redeemed_in_carts = CartPosition.objects.filter(
+                Q(voucher=voucher) & Q(event=self.context['event']) & Q(expires__gte=now())
+            )
+            cart_count = redeemed_in_carts.count()
+            v_avail = voucher.max_usages - voucher.redeemed - cart_count
+            if v_avail < 1:
+                raise ValidationError('The specified voucher has already been used the maximum number of times.')
+
+            validated_data['voucher'] = voucher
+
+        if validated_data.get('seat'):
+            if not validated_data['seat'].is_available(
+                sales_channel=validated_data.get('sales_channel', 'web'),
+                distance_ignore_cart_id=validated_data['cart_id'],
+                ignore_voucher_id=validated_data['voucher'].pk if validated_data.get('voucher') else None,
+            ):
+                raise ValidationError(
+                    gettext_lazy('The selected seat "{seat}" is not available.').format(seat=validated_data['seat'].name))
+
         validated_data.pop('sales_channel')
+        # todo: does this make sense?
+        validated_data['custom_price_input'] = validated_data['price']
+        # todo: listed price, etc?
+        # currently does not matter because there is no way to transform an API cart position into an order that keeps
+        # prices, cart positions are just quota/voucher placeholders
+        validated_data['custom_price_input_is_net'] = not validated_data.pop('includes_tax', True)
         cp = CartPosition.objects.create(event=self.context['event'], **validated_data)
 
         for answ_data in answers_data:

src/pretix/api/serializers/checkin.py

@@ -60,7 +60,7 @@ class CheckinListSerializer(I18nAwareModelSerializer):
         full_data = self.to_internal_value(self.to_representation(self.instance)) if self.instance else {}
         full_data.update(data)
 
-        for item in full_data.get('limit_products'):
+        for item in full_data.get('limit_products', []):
             if event != item.event:
                 raise ValidationError(_('One or more items do not belong to this event.'))
 

src/pretix/api/serializers/discount.py

@@ -0,0 +1,49 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io GmbH and contributors
+#
+# This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General
+# Public License as published by the Free Software Foundation in version 3 of the License.
+#
+# ADDITIONAL TERMS APPLY: Pursuant to Section 7 of the GNU Affero General Public License, additional terms are
+# applicable granting you additional permissions and placing additional restrictions on your usage of this software.
+# Please refer to the pretix LICENSE file to obtain the full terms applicable to this work. If you did not receive
+# this file, see <https://pretix.eu/about/en/license>.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
+# <https://www.gnu.org/licenses/>.
+#
+
+from pretix.api.serializers.i18n import I18nAwareModelSerializer
+from pretix.base.models import Discount
+
+
+class DiscountSerializer(I18nAwareModelSerializer):
+
+    class Meta:
+        model = Discount
+        fields = ('id', 'active', 'internal_name', 'position', 'sales_channels', 'available_from',
+                  'available_until', 'subevent_mode', 'condition_all_products', 'condition_limit_products',
+                  'condition_apply_to_addons', 'condition_min_count', 'condition_min_value',
+                  'benefit_discount_matching_percent', 'benefit_only_apply_to_cheapest_n_matches',
+                  'condition_ignore_voucher_discounted')
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.fields['condition_limit_products'].queryset = self.context['event'].items.all()
+
+    def validate(self, data):
+        data = super().validate(data)
+
+        full_data = self.to_internal_value(self.to_representation(self.instance)) if self.instance else {}
+        full_data.update(data)
+
+        Discount.validate_config(full_data)
+
+        return data

src/pretix/api/serializers/event.py

@@ -637,7 +637,7 @@ class SubEventSerializer(I18nAwareModelSerializer):
 class TaxRuleSerializer(CountryFieldMixin, I18nAwareModelSerializer):
     class Meta:
         model = TaxRule
-        fields = ('id', 'name', 'rate', 'price_includes_tax', 'eu_reverse_charge', 'home_country')
+        fields = ('id', 'name', 'rate', 'price_includes_tax', 'eu_reverse_charge', 'home_country', 'internal_name', 'keep_gross_if_rate_changes')
 
 
 class EventSettingsSerializer(SettingsSerializer):
@@ -713,7 +713,6 @@ class EventSettingsSerializer(SettingsSerializer):
         'ticket_download_require_validated_email',
         'ticket_secret_length',
         'mail_prefix',
-        'mail_from',
         'mail_from_name',
         'mail_attach_ical',
         'mail_attach_tickets',

src/pretix/api/serializers/item.py

@@ -58,8 +58,9 @@ class InlineItemVariationSerializer(I18nAwareModelSerializer):
     class Meta:
         model = ItemVariation
         fields = ('id', 'value', 'active', 'description',
-                  'position', 'default_price', 'price', 'original_price',
-                  'require_membership', 'require_membership_types', 'require_membership_hidden', 'available_from', 'available_until',
+                  'position', 'default_price', 'price', 'original_price', 'require_approval',
+                  'require_membership', 'require_membership_types',
+                  'require_membership_hidden', 'available_from', 'available_until',
                   'sales_channels', 'hide_without_voucher',)
 
     def __init__(self, *args, **kwargs):
@@ -74,8 +75,9 @@ class ItemVariationSerializer(I18nAwareModelSerializer):
     class Meta:
         model = ItemVariation
         fields = ('id', 'value', 'active', 'description',
-                  'position', 'default_price', 'price', 'original_price',
-                  'require_membership', 'require_membership_types', 'require_membership_hidden', 'available_from', 'available_until',
+                  'position', 'default_price', 'price', 'original_price', 'require_approval',
+                  'require_membership', 'require_membership_types',
+                  'require_membership_hidden', 'available_from', 'available_until',
                   'sales_channels', 'hide_without_voucher',)
 
     def __init__(self, *args, **kwargs):
@@ -249,9 +251,12 @@ class ItemSerializer(I18nAwareModelSerializer):
         bundles_data = validated_data.pop('bundles') if 'bundles' in validated_data else {}
         meta_data = validated_data.pop('meta_data', None)
         picture = validated_data.pop('picture', None)
+        require_membership_types = validated_data.pop('require_membership_types', [])
         item = Item.objects.create(**validated_data)
         if picture:
             item.picture.save(os.path.basename(picture.name), picture)
+        if require_membership_types:
+            item.require_membership_types.add(*require_membership_types)
 
         for variation_data in variations_data:
             require_membership_types = variation_data.pop('require_membership_types', [])

src/pretix/api/serializers/order.py

@@ -56,7 +56,9 @@ from pretix.base.models.orders import (
 from pretix.base.pdf import get_images, get_variables
 from pretix.base.services.cart import error_messages
 from pretix.base.services.locking import NoLockManager
-from pretix.base.services.pricing import get_price
+from pretix.base.services.pricing import (
+    apply_discounts, get_line_price, get_listed_price, is_included_for_free,
+)
 from pretix.base.settings import COUNTRIES_WITH_STATE_IN_ADDRESS
 from pretix.base.signals import register_ticket_outputs
 from pretix.multidomain.urlreverse import build_absolute_uri
@@ -424,88 +426,7 @@ class OrderPositionSerializer(I18nAwareModelSerializer):
             self.fields.pop('pdf_data', None)
 
     def validate(self, data):
-        if data.get('attendee_name') and data.get('attendee_name_parts'):
-            raise ValidationError(
-                {'attendee_name': ['Do not specify attendee_name if you specified attendee_name_parts.']}
-            )
-        if data.get('attendee_name_parts') and '_scheme' not in data.get('attendee_name_parts'):
-            data['attendee_name_parts']['_scheme'] = self.context['request'].event.settings.name_scheme
-
-        if data.get('country'):
-            if not pycountry.countries.get(alpha_2=data.get('country').code):
-                raise ValidationError(
-                    {'country': ['Invalid country code.']}
-                )
-
-        if data.get('state'):
-            cc = str(data.get('country') or self.instance.country or '')
-            if cc not in COUNTRIES_WITH_STATE_IN_ADDRESS:
-                raise ValidationError(
-                    {'state': ['States are not supported in country "{}".'.format(cc)]}
-                )
-            if not pycountry.subdivisions.get(code=cc + '-' + data.get('state')):
-                raise ValidationError(
-                    {'state': ['"{}" is not a known subdivision of the country "{}".'.format(data.get('state'), cc)]}
-                )
-        return data
-
-    def update(self, instance, validated_data):
-        # Even though all fields that shouldn't be edited are marked as read_only in the serializer
-        # (hopefully), we'll be extra careful here and be explicit about the model fields we update.
-        update_fields = [
-            'attendee_name_parts', 'company', 'street', 'zipcode', 'city', 'country',
-            'state', 'attendee_email',
-        ]
-        answers_data = validated_data.pop('answers', None)
-
-        name = validated_data.pop('attendee_name', '')
-        if name and not validated_data.get('attendee_name_parts'):
-            validated_data['attendee_name_parts'] = {
-                '_legacy': name
-            }
-
-        for attr, value in validated_data.items():
-            if attr in update_fields:
-                setattr(instance, attr, value)
-
-        instance.save(update_fields=update_fields)
-
-        if answers_data is not None:
-            qs_seen = set()
-            answercache = {
-                a.question_id: a for a in instance.answers.all()
-            }
-            for answ_data in answers_data:
-                options = answ_data.pop('options', [])
-                if answ_data['question'].pk in qs_seen:
-                    raise ValidationError(f'Question {answ_data["question"]} was sent twice.')
-                if answ_data['question'].pk in answercache:
-                    a = answercache[answ_data['question'].pk]
-                    if isinstance(answ_data['answer'], File):
-                        a.file.save(answ_data['answer'].name, answ_data['answer'], save=False)
-                        a.answer = 'file://' + a.file.name
-                    elif a.answer.startswith('file://') and answ_data['answer'] == "file:keep":
-                        pass  # keep current file
-                    else:
-                        for attr, value in answ_data.items():
-                            setattr(a, attr, value)
-                    a.save()
-                else:
-                    if isinstance(answ_data['answer'], File):
-                        an = answ_data.pop('answer')
-                        a = instance.answers.create(**answ_data, answer='')
-                        a.file.save(os.path.basename(an.name), an, save=False)
-                        a.answer = 'file://' + a.file.name
-                        a.save()
-                    else:
-                        a = instance.answers.create(**answ_data)
-                a.options.set(options)
-                qs_seen.add(a.question_id)
-            for qid, a in answercache.items():
-                if qid not in qs_seen:
-                    a.delete()
-
-        return instance
+        raise TypeError("this serializer is readonly")
 
 
 class RequireAttentionField(serializers.Field):
@@ -593,7 +514,7 @@ class OrderPaymentDateField(serializers.DateField):
 class OrderFeeSerializer(I18nAwareModelSerializer):
     class Meta:
         model = OrderFee
-        fields = ('fee_type', 'value', 'description', 'internal_type', 'tax_rate', 'tax_value', 'tax_rule', 'canceled')
+        fields = ('id', 'fee_type', 'value', 'description', 'internal_type', 'tax_rate', 'tax_value', 'tax_rule', 'canceled')
 
 
 class PaymentURLField(serializers.URLField):
@@ -934,7 +855,8 @@ class OrderCreateSerializer(I18nAwareModelSerializer):
     consume_carts = serializers.ListField(child=serializers.CharField(), required=False)
     force = serializers.BooleanField(default=False, required=False)
     payment_date = serializers.DateTimeField(required=False, allow_null=True)
-    send_email = serializers.BooleanField(default=False, required=False)
+    send_email = serializers.BooleanField(default=False, required=False, allow_null=True)
+    require_approval = serializers.BooleanField(default=False, required=False)
     simulate = serializers.BooleanField(default=False, required=False)
     customer = serializers.SlugRelatedField(slug_field='identifier', queryset=Customer.objects.none(), required=False)
 
@@ -947,7 +869,7 @@ class OrderCreateSerializer(I18nAwareModelSerializer):
         model = Order
         fields = ('code', 'status', 'testmode', 'email', 'phone', 'locale', 'payment_provider', 'fees', 'comment', 'sales_channel',
                   'invoice_address', 'positions', 'checkin_attention', 'payment_info', 'payment_date', 'consume_carts',
-                  'force', 'send_email', 'simulate', 'customer', 'custom_followup_at')
+                  'force', 'send_email', 'simulate', 'customer', 'custom_followup_at', 'require_approval')
 
     def validate_payment_provider(self, pp):
         if pp is None:
@@ -1041,6 +963,8 @@ class OrderCreateSerializer(I18nAwareModelSerializer):
         force = validated_data.pop('force', False)
         simulate = validated_data.pop('simulate', False)
         self._send_mail = validated_data.pop('send_email', False)
+        if self._send_mail is None:
+            self._send_mail = validated_data.get('sales_channel') in self.context['event'].settings.mail_sales_channel_placed_paid
 
         if 'invoice_address' in validated_data:
             iadata = validated_data.pop('invoice_address')
@@ -1053,8 +977,18 @@ class OrderCreateSerializer(I18nAwareModelSerializer):
         else:
             ia = None
 
+        lock_required = False
+        for pos_data in positions_data:
+            pos_data['_quotas'] = list(
+                pos_data.get('variation').quotas.filter(subevent=pos_data.get('subevent'))
+                if pos_data.get('variation')
+                else pos_data.get('item').quotas.filter(subevent=pos_data.get('subevent'))
+            )
+            if pos_data.get('voucher') or pos_data.get('seat') or any(q.size is not None for q in pos_data['_quotas']):
+                lock_required = True
+
         lockfn = self.context['event'].lock
-        if simulate:
+        if simulate or not lock_required:
             lockfn = NoLockManager
         with lockfn() as now_dt:
             free_seats = set()
@@ -1118,29 +1052,18 @@ class OrderCreateSerializer(I18nAwareModelSerializer):
 
                     if v.budget is not None:
                         price = pos_data.get('price')
+                        listed_price = get_listed_price(pos_data.get('item'), pos_data.get('variation'), pos_data.get('subevent'))
+
+                        if pos_data.get('voucher'):
+                            price_after_voucher = pos_data.get('voucher').calculate_price(listed_price)
+                        else:
+                            price_after_voucher = listed_price
                         if price is None:
-                            price = get_price(
-                                item=pos_data.get('item'),
-                                variation=pos_data.get('variation'),
-                                voucher=v,
-                                custom_price=None,
-                                subevent=pos_data.get('subevent'),
-                                addon_to=pos_data.get('addon_to'),
-                                invoice_address=ia,
-                            ).gross
-                        pbv = get_price(
-                            item=pos_data['item'],
-                            variation=pos_data.get('variation'),
-                            voucher=None,
-                            custom_price=None,
-                            subevent=pos_data.get('subevent'),
-                            addon_to=pos_data.get('addon_to'),
-                            invoice_address=ia,
-                        )
+                            price = price_after_voucher
 
                         if v not in v_budget:
                             v_budget[v] = v.budget - v.budget_used()
-                        disc = pbv.gross - price
+                        disc = max(listed_price - price, 0)
                         if disc > v_budget[v]:
                             new_disc = v_budget[v]
                             v_budget[v] -= new_disc
@@ -1189,9 +1112,7 @@ class OrderCreateSerializer(I18nAwareModelSerializer):
                                 str(pos_data.get('item'))
                             )]
 
-                    new_quotas = (pos_data.get('variation').quotas.filter(subevent=pos_data.get('subevent'))
-                                  if pos_data.get('variation')
-                                  else pos_data.get('item').quotas.filter(subevent=pos_data.get('subevent')))
+                    new_quotas = pos_data['_quotas']
                     if len(new_quotas) == 0:
                         errs[i]['item'] = [gettext_lazy('The product "{}" is not assigned to a quota.').format(
                             str(pos_data.get('item'))
@@ -1219,6 +1140,8 @@ class OrderCreateSerializer(I18nAwareModelSerializer):
             order.set_expires(subevents=[p.get('subevent') for p in positions_data])
             order.meta_info = "{}"
             order.total = Decimal('0.00')
+            if validated_data.get('require_approval') is not None:
+                order.require_approval = validated_data['require_approval']
             if simulate:
                 order = WrappedModel(order)
                 order.last_modified = now()
@@ -1234,52 +1157,85 @@ class OrderCreateSerializer(I18nAwareModelSerializer):
                     order.invoice_address = ia
                     ia.last_modified = now()
 
+            # Generate position objects
             pos_map = {}
             for pos_data in positions_data:
-                answers_data = pos_data.pop('answers', [])
                 addon_to = pos_data.pop('addon_to', None)
                 attendee_name = pos_data.pop('attendee_name', '')
                 if attendee_name and not pos_data.get('attendee_name_parts'):
                     pos_data['attendee_name_parts'] = {
                         '_legacy': attendee_name
                     }
-                pos = OrderPosition(**pos_data)
+                pos = OrderPosition(**{k: v for k, v in pos_data.items() if k != 'answers' and k != '_quotas'})
                 if simulate:
                     pos.order = order._wrapped
                 else:
                     pos.order = order
                 if addon_to:
                     if simulate:
-                        pos.addon_to = pos_map[addon_to]._wrapped
+                        pos.addon_to = pos_map[addon_to]
                     else:
                         pos.addon_to = pos_map[addon_to]
 
-                if pos.price is None:
-                    price = get_price(
-                        item=pos.item,
-                        variation=pos.variation,
-                        voucher=pos.voucher,
-                        custom_price=None,
-                        subevent=pos.subevent,
-                        addon_to=pos.addon_to,
-                        invoice_address=ia,
-                    )
-                    pos.price = price.gross
-                    pos.tax_rate = price.rate
-                    pos.tax_value = price.tax
-                    pos.tax_rule = pos.item.tax_rule
-                else:
-                    pos._calculate_tax()
+                pos_map[pos.positionid] = pos
+                pos_data['__instance'] = pos
 
-                pos.price_before_voucher = get_price(
-                    item=pos.item,
-                    variation=pos.variation,
-                    voucher=None,
-                    custom_price=None,
-                    subevent=pos.subevent,
-                    addon_to=pos.addon_to,
-                    invoice_address=ia,
-                ).gross
+            # Calculate prices if not set
+            for pos_data in positions_data:
+                pos = pos_data['__instance']
+                if pos.addon_to_id and is_included_for_free(pos.item, pos.addon_to):
+                    listed_price = Decimal('0.00')
+                else:
+                    listed_price = get_listed_price(pos.item, pos.variation, pos.subevent)
+
+                if pos.price is None:
+                    if pos.voucher:
+                        price_after_voucher = pos.voucher.calculate_price(listed_price)
+                    else:
+                        price_after_voucher = listed_price
+
+                    line_price = get_line_price(
+                        price_after_voucher=price_after_voucher,
+                        custom_price_input=None,
+                        custom_price_input_is_net=False,
+                        tax_rule=pos.item.tax_rule,
+                        invoice_address=ia,
+                        bundled_sum=Decimal('0.00'),
+                    )
+                    pos.price = line_price.gross
+                    pos._auto_generated_price = True
+                else:
+                    if pos.voucher:
+                        if not pos.item.tax_rule or pos.item.tax_rule.price_includes_tax:
+                            price_after_voucher = max(pos.price, pos.voucher.calculate_price(listed_price))
+                        else:
+                            price_after_voucher = max(pos.price - pos.tax_value, pos.voucher.calculate_price(listed_price))
+                    else:
+                        price_after_voucher = listed_price
+                    pos._auto_generated_price = False
+                pos._voucher_discount = listed_price - price_after_voucher
+                if pos.voucher:
+                    pos.voucher_budget_use = max(listed_price - price_after_voucher, Decimal('0.00'))
+
+            order_positions = [pos_data['__instance'] for pos_data in positions_data]
+            discount_results = apply_discounts(
+                self.context['event'],
+                order.sales_channel,
+                [
+                    (cp.item_id, cp.subevent_id, cp.price, bool(cp.addon_to), cp.is_bundled, pos._voucher_discount)
+                    for cp in order_positions
+                ]
+            )
+            for cp, (new_price, discount) in zip(order_positions, discount_results):
+                if new_price != pos.price and pos._auto_generated_price:
+                    pos.price = new_price
+                pos.discount = discount
+
+            # Save instances
+            for pos_data in positions_data:
+                answers_data = pos_data.pop('answers', [])
+                pos = pos_data['__instance']
+                pos._calculate_tax()
 
                 if simulate:
                     pos = WrappedModel(pos)
@@ -1292,6 +1248,7 @@ class OrderCreateSerializer(I18nAwareModelSerializer):
                         answers.append(answ)
                     pos.answers = answers
                     pos.pseudonymization_id = "PREVIEW"
+                    pos_map[pos.positionid] = pos
                 else:
                     if pos.voucher:
                         Voucher.objects.filter(pk=pos.voucher.pk).update(redeemed=F('redeemed') + 1)
@@ -1314,7 +1271,6 @@ class OrderCreateSerializer(I18nAwareModelSerializer):
                         else:
                             answ = pos.answers.create(**answ_data)
                             answ.options.add(*options)
-                pos_map[pos.positionid] = pos
 
             if not simulate:
                 for cp in delete_cps:
@@ -1356,14 +1312,18 @@ class OrderCreateSerializer(I18nAwareModelSerializer):
                     f.order = order._wrapped if simulate else order
                     f._calculate_tax()
                     fees.append(f)
-                    if not simulate:
+                    if simulate:
+                        f.id = 0
+                    else:
                         f.save()
             else:
                 f = OrderFee(**fee_data)
                 f.order = order._wrapped if simulate else order
                 f._calculate_tax()
                 fees.append(f)
-                if not simulate:
+                if simulate:
+                    f.id = 0
+                else:
                     f.save()
 
         order.total += sum([f.value for f in fees])
@@ -1426,7 +1386,7 @@ class InlineInvoiceLineSerializer(I18nAwareModelSerializer):
 
     class Meta:
         model = InvoiceLine
-        fields = ('position', 'description', 'item', 'variation', 'attendee_name', 'event_date_from',
+        fields = ('position', 'description', 'item', 'variation', 'subevent', 'attendee_name', 'event_date_from',
                   'event_date_to', 'gross_value', 'tax_value', 'tax_rate', 'tax_name', 'fee_type',
                   'fee_internal_type', 'event_location')
 

src/pretix/api/serializers/orderchange.py

@@ -0,0 +1,424 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io GmbH and contributors
+#
+# This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General
+# Public License as published by the Free Software Foundation in version 3 of the License.
+#
+# ADDITIONAL TERMS APPLY: Pursuant to Section 7 of the GNU Affero General Public License, additional terms are
+# applicable granting you additional permissions and placing additional restrictions on your usage of this software.
+# Please refer to the pretix LICENSE file to obtain the full terms applicable to this work. If you did not receive
+# this file, see <https://pretix.eu/about/en/license>.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
+# <https://www.gnu.org/licenses/>.
+#
+import logging
+import os
+
+import pycountry
+from django.core.files import File
+from rest_framework import serializers
+from rest_framework.exceptions import ValidationError
+
+from pretix.api.serializers.order import (
+    AnswerCreateSerializer, AnswerSerializer, CompatibleCountryField,
+    OrderPositionCreateSerializer,
+)
+from pretix.base.models import ItemVariation, Order, OrderFee, OrderPosition
+from pretix.base.services.orders import OrderError
+from pretix.base.settings import COUNTRIES_WITH_STATE_IN_ADDRESS
+
+logger = logging.getLogger(__name__)
+
+
+class OrderPositionCreateForExistingOrderSerializer(OrderPositionCreateSerializer):
+    order = serializers.SlugRelatedField(slug_field='code', queryset=Order.objects.none(), required=True, allow_null=False)
+    answers = AnswerCreateSerializer(many=True, required=False)
+    addon_to = serializers.IntegerField(required=False, allow_null=True)
+    secret = serializers.CharField(required=False)
+    attendee_name = serializers.CharField(required=False, allow_null=True)
+    seat = serializers.CharField(required=False, allow_null=True)
+    price = serializers.DecimalField(required=False, allow_null=True, decimal_places=2,
+                                     max_digits=10)
+    country = CompatibleCountryField(source='*')
+
+    class Meta:
+        model = OrderPosition
+        fields = ('order', 'item', 'variation', 'price', 'attendee_name', 'attendee_name_parts', 'attendee_email',
+                  'company', 'street', 'zipcode', 'city', 'country', 'state',
+                  'secret', 'addon_to', 'subevent', 'answers', 'seat')
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        if not self.context:
+            return
+        self.fields['order'].queryset = self.context['event'].orders.all()
+        self.fields['item'].queryset = self.context['event'].items.all()
+        self.fields['subevent'].queryset = self.context['event'].subevents.all()
+        self.fields['seat'].queryset = self.context['event'].seats.all()
+        self.fields['variation'].queryset = ItemVariation.objects.filter(item__event=self.context['event'])
+        if 'order' in self.context:
+            del self.fields['order']
+
+    def validate(self, data):
+        data = super().validate(data)
+        if data.get('addon_to'):
+            try:
+                data['addon_to'] = data['order'].positions.get(positionid=data['addon_to'])
+            except OrderPosition.DoesNotExist:
+                raise ValidationError({
+                    'addon_to': ['addon_to refers to an unknown position ID for this order.']
+                })
+        return data
+
+    def create(self, validated_data):
+        ocm = self.context['ocm']
+
+        try:
+            ocm.add_position(
+                item=validated_data['item'],
+                variation=validated_data.get('variation'),
+                price=validated_data.get('price'),
+                addon_to=validated_data.get('addon_to'),
+                subevent=validated_data.get('subevent'),
+                seat=validated_data.get('seat'),
+            )
+            if self.context.get('commit', True):
+                ocm.commit()
+                return validated_data['order'].positions.order_by('-positionid').first()
+            else:
+                return OrderPosition()  # fake to appease DRF
+        except OrderError as e:
+            raise ValidationError(str(e))
+
+
+class OrderPositionInfoPatchSerializer(serializers.ModelSerializer):
+    answers = AnswerSerializer(many=True)
+    country = CompatibleCountryField(source='*')
+    attendee_name = serializers.CharField(required=False)
+
+    class Meta:
+        model = OrderPosition
+        fields = (
+            'attendee_name', 'attendee_name_parts', 'company', 'street', 'zipcode', 'city', 'country',
+            'state', 'attendee_email', 'answers',
+        )
+
+    def validate(self, data):
+        if data.get('attendee_name') and data.get('attendee_name_parts'):
+            raise ValidationError(
+                {'attendee_name': ['Do not specify attendee_name if you specified attendee_name_parts.']}
+            )
+        if data.get('attendee_name_parts') and '_scheme' not in data.get('attendee_name_parts'):
+            data['attendee_name_parts']['_scheme'] = self.context['request'].event.settings.name_scheme
+
+        if data.get('country'):
+            if not pycountry.countries.get(alpha_2=data.get('country').code):
+                raise ValidationError(
+                    {'country': ['Invalid country code.']}
+                )
+
+        if data.get('state'):
+            cc = str(data.get('country') or self.instance.country or '')
+            if cc not in COUNTRIES_WITH_STATE_IN_ADDRESS:
+                raise ValidationError(
+                    {'state': ['States are not supported in country "{}".'.format(cc)]}
+                )
+            if not pycountry.subdivisions.get(code=cc + '-' + data.get('state')):
+                raise ValidationError(
+                    {'state': ['"{}" is not a known subdivision of the country "{}".'.format(data.get('state'), cc)]}
+                )
+        return data
+
+    def update(self, instance, validated_data):
+        answers_data = validated_data.pop('answers', None)
+
+        name = validated_data.pop('attendee_name', '')
+        if name and not validated_data.get('attendee_name_parts'):
+            validated_data['attendee_name_parts'] = {
+                '_legacy': name
+            }
+
+        for attr, value in validated_data.items():
+            if attr in self.fields:
+                setattr(instance, attr, value)
+
+        instance.save(update_fields=list(validated_data.keys()))
+
+        if answers_data is not None:
+            qs_seen = set()
+            answercache = {
+                a.question_id: a for a in instance.answers.all()
+            }
+            for answ_data in answers_data:
+                options = answ_data.pop('options', [])
+                if answ_data['question'].pk in qs_seen:
+                    raise ValidationError(f'Question {answ_data["question"]} was sent twice.')
+                if answ_data['question'].pk in answercache:
+                    a = answercache[answ_data['question'].pk]
+                    if isinstance(answ_data['answer'], File):
+                        a.file.save(answ_data['answer'].name, answ_data['answer'], save=False)
+                        a.answer = 'file://' + a.file.name
+                    elif a.answer.startswith('file://') and answ_data['answer'] == "file:keep":
+                        pass  # keep current file
+                    else:
+                        for attr, value in answ_data.items():
+                            setattr(a, attr, value)
+                    a.save()
+                else:
+                    if isinstance(answ_data['answer'], File):
+                        an = answ_data.pop('answer')
+                        a = instance.answers.create(**answ_data, answer='')
+                        a.file.save(os.path.basename(an.name), an, save=False)
+                        a.answer = 'file://' + a.file.name
+                        a.save()
+                    else:
+                        a = instance.answers.create(**answ_data)
+                a.options.set(options)
+                qs_seen.add(a.question_id)
+            for qid, a in answercache.items():
+                if qid not in qs_seen:
+                    a.delete()
+
+        return instance
+
+
+class OrderPositionChangeSerializer(serializers.ModelSerializer):
+    seat = serializers.CharField(source='seat.seat_guid', allow_null=True, required=False)
+
+    class Meta:
+        model = OrderPosition
+        fields = (
+            'item', 'variation', 'subevent', 'seat', 'price', 'tax_rule',
+        )
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        if not self.context:
+            return
+        self.fields['item'].queryset = self.context['event'].items.all()
+        self.fields['subevent'].queryset = self.context['event'].subevents.all()
+        self.fields['tax_rule'].queryset = self.context['event'].tax_rules.all()
+        if kwargs.get('partial'):
+            for k, v in self.fields.items():
+                self.fields[k].required = False
+
+    def validate_item(self, item):
+        if item.event != self.context['event']:
+            raise ValidationError(
+                'The specified item does not belong to this event.'
+            )
+        return item
+
+    def validate_subevent(self, subevent):
+        if self.context['event'].has_subevents:
+            if not subevent:
+                raise ValidationError(
+                    'You need to set a subevent.'
+                )
+            if subevent.event != self.context['event']:
+                raise ValidationError(
+                    'The specified subevent does not belong to this event.'
+                )
+        elif subevent:
+            raise ValidationError(
+                'You cannot set a subevent for this event.'
+            )
+        return subevent
+
+    def validate(self, data, instance=None):
+        instance = instance or self.instance
+        if instance is None:
+            return data  # needs to be done later
+        if data.get('item', instance.item):
+            if data.get('item', instance.item).has_variations:
+                if not data.get('variation', instance.variation):
+                    raise ValidationError({'variation': ['You should specify a variation for this item.']})
+                else:
+                    if data.get('variation', instance.variation).item != data.get('item', instance.item):
+                        raise ValidationError(
+                            {'variation': ['The specified variation does not belong to the specified item.']}
+                        )
+            elif data.get('variation', instance.variation):
+                raise ValidationError(
+                    {'variation': ['You cannot specify a variation for this item.']}
+                )
+
+        return data
+
+    def update(self, instance, validated_data):
+        ocm = self.context['ocm']
+        current_seat = {'seat_guid': instance.seat.seat_guid} if instance.seat else None
+        item = validated_data.get('item', instance.item)
+        variation = validated_data.get('variation', instance.variation)
+        subevent = validated_data.get('subevent', instance.subevent)
+        price = validated_data.get('price', instance.price)
+        seat = validated_data.get('seat', current_seat)
+        tax_rule = validated_data.get('tax_rule', instance.tax_rule)
+
+        change_item = None
+        if item != instance.item or variation != instance.variation:
+            change_item = (item, variation)
+
+        change_subevent = None
+        if self.context['event'].has_subevents and subevent != instance.subevent:
+            change_subevent = (subevent,)
+
+        try:
+            if change_item is not None and change_subevent is not None:
+                ocm.change_item_and_subevent(instance, *change_item, *change_subevent)
+            elif change_item is not None:
+                ocm.change_item(instance, *change_item)
+            elif change_subevent is not None:
+                ocm.change_subevent(instance, *change_subevent)
+
+            if seat != current_seat or change_subevent:
+                ocm.change_seat(instance, seat['seat_guid'] if seat else None)
+
+            if price != instance.price:
+                ocm.change_price(instance, price)
+
+            if tax_rule != instance.tax_rule:
+                ocm.change_tax_rule(instance, tax_rule)
+
+            if self.context.get('commit', True):
+                ocm.commit()
+                instance.refresh_from_db()
+        except OrderError as e:
+            raise ValidationError(str(e))
+        return instance
+
+
+class PatchPositionSerializer(serializers.Serializer):
+    position = serializers.PrimaryKeyRelatedField(queryset=OrderPosition.all.none())
+
+    def validate_position(self, value):
+        self.fields['body'].instance = value  # hack around DRFs validation order
+        return value
+
+    def validate(self, data):
+        OrderPositionChangeSerializer(context=self.context, partial=True).validate(data['body'], data['position'])
+        return data
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.fields['position'].queryset = self.context['order'].positions.all()
+        self.fields['body'] = OrderPositionChangeSerializer(context=self.context, partial=True)
+
+
+class SelectPositionSerializer(serializers.Serializer):
+    position = serializers.PrimaryKeyRelatedField(queryset=OrderPosition.all.none())
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.fields['position'].queryset = self.context['order'].positions.all()
+
+
+class OrderFeeChangeSerializer(serializers.ModelSerializer):
+
+    class Meta:
+        model = OrderFee
+        fields = (
+            'value',
+        )
+
+    def update(self, instance, validated_data):
+        ocm = self.context['ocm']
+        value = validated_data.get('value', instance.value)
+
+        try:
+            if value != instance.value:
+                ocm.change_fee(instance, value)
+
+            if self.context.get('commit', True):
+                ocm.commit()
+                instance.refresh_from_db()
+        except OrderError as e:
+            raise ValidationError(str(e))
+        return instance
+
+
+class PatchFeeSerializer(serializers.Serializer):
+    fee = serializers.PrimaryKeyRelatedField(queryset=OrderFee.all.none())
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.fields['fee'].queryset = self.context['order'].fees.all()
+        self.fields['body'] = OrderFeeChangeSerializer(context=self.context)
+
+
+class SelectFeeSerializer(serializers.Serializer):
+    fee = serializers.PrimaryKeyRelatedField(queryset=OrderFee.all.none())
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        if not self.context:
+            return
+        self.fields['fee'].queryset = self.context['order'].fees.all()
+
+
+class OrderChangeOperationSerializer(serializers.Serializer):
+    send_email = serializers.BooleanField(default=False, required=False)
+    reissue_invoice = serializers.BooleanField(default=True, required=False)
+    recalculate_taxes = serializers.ChoiceField(default=None, allow_null=True, required=False, choices=[
+        ('keep_net', 'keep_net'),
+        ('keep_gross', 'keep_gross'),
+    ])
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(self, *args, **kwargs)
+        self.fields['patch_positions'] = PatchPositionSerializer(
+            many=True, required=False, context=self.context
+        )
+        self.fields['cancel_positions'] = SelectPositionSerializer(
+            many=True, required=False, context=self.context
+        )
+        self.fields['create_positions'] = OrderPositionCreateForExistingOrderSerializer(
+            many=True, required=False, context=self.context
+        )
+        self.fields['split_positions'] = SelectPositionSerializer(
+            many=True, required=False, context=self.context
+        )
+        self.fields['patch_fees'] = PatchFeeSerializer(
+            many=True, required=False, context=self.context
+        )
+        self.fields['cancel_fees'] = SelectFeeSerializer(
+            many=True, required=False, context=self.context
+        )
+
+    def validate(self, data):
+        seen_positions = set()
+        for d in data.get('patch_positions', []):
+            print(d, seen_positions)
+            if d['position'] in seen_positions:
+                raise ValidationError({'patch_positions': ['You have specified the same object twice.']})
+            seen_positions.add(d['position'])
+        seen_positions = set()
+        for d in data.get('cancel_positions', []):
+            if d['position'] in seen_positions:
+                raise ValidationError({'cancel_positions': ['You have specified the same object twice.']})
+            seen_positions.add(d['position'])
+        seen_positions = set()
+        for d in data.get('split_positions', []):
+            if d['position'] in seen_positions:
+                raise ValidationError({'split_positions': ['You have specified the same object twice.']})
+            seen_positions.add(d['position'])
+        seen_fees = set()
+        for d in data.get('patch_fees', []):
+            if d['fee'] in seen_fees:
+                raise ValidationError({'patch_fees': ['You have specified the same object twice.']})
+            seen_positions.add(d['fee'])
+        seen_fees = set()
+        for d in data.get('cancel_fees', []):
+            if d['fee'] in seen_fees:
+                raise ValidationError({'cancel_fees': ['You have specified the same object twice.']})
+            seen_positions.add(d['fee'])
+
+        return data

src/pretix/api/serializers/organizer.py

@@ -71,8 +71,8 @@ class CustomerSerializer(I18nAwareModelSerializer):
 
     class Meta:
         model = Customer
-        fields = ('identifier', 'email', 'name', 'name_parts', 'is_active', 'is_verified', 'last_login', 'date_joined',
-                  'locale', 'last_modified')
+        fields = ('identifier', 'external_identifier', 'email', 'name', 'name_parts', 'is_active', 'is_verified', 'last_login', 'date_joined',
+                  'locale', 'last_modified', 'notes')
 
 
 class MembershipTypeSerializer(I18nAwareModelSerializer):
@@ -296,7 +296,14 @@ class OrganizerSettingsSerializer(SettingsSerializer):
         'theme_round_borders',
         'primary_font',
         'organizer_logo_image_inherit',
-        'organizer_logo_image'
+        'organizer_logo_image',
+        'privacy_url',
+        'cookie_consent',
+        'cookie_consent_dialog_title',
+        'cookie_consent_dialog_text',
+        'cookie_consent_dialog_text_secondary',
+        'cookie_consent_dialog_button_yes',
+        'cookie_consent_dialog_button_no',
     ]
 
     def __init__(self, *args, **kwargs):

src/pretix/api/urls.py

@@ -41,8 +41,8 @@ from rest_framework import routers
 from pretix.api.views import cart
 
 from .views import (
-    checkin, device, event, exporters, item, oauth, order, organizer, upload,
-    user, version, voucher, waitinglist, webhooks,
+    checkin, device, discount, event, exporters, idempotency, item, oauth,
+    order, organizer, upload, user, version, voucher, waitinglist, webhooks,
 )
 
 router = routers.DefaultRouter()
@@ -72,6 +72,7 @@ event_router.register(r'clone', event.CloneEventViewSet)
 event_router.register(r'items', item.ItemViewSet)
 event_router.register(r'categories', item.ItemCategoryViewSet)
 event_router.register(r'questions', item.QuestionViewSet)
+event_router.register(r'discounts', discount.DiscountViewSet)
 event_router.register(r'quotas', item.QuotaViewSet)
 event_router.register(r'vouchers', voucher.VoucherViewSet)
 event_router.register(r'orders', order.OrderViewSet)
@@ -132,6 +133,7 @@ urlpatterns = [
     re_path(r"^device/roll$", device.RollKeyView.as_view(), name="device.roll"),
     re_path(r"^device/revoke$", device.RevokeKeyView.as_view(), name="device.revoke"),
     re_path(r"^device/eventselection$", device.EventSelectionView.as_view(), name="device.eventselection"),
+    re_path(r"^idempotency_query$", idempotency.IdempotencyQueryView.as_view(), name="idempotency.query"),
     re_path(r"^upload$", upload.UploadView.as_view(), name="upload"),
     re_path(r"^me$", user.MeView.as_view(), name="user.me"),
     re_path(r"^version$", version.VersionView.as_view(), name="version"),

src/pretix/api/views/checkin.py

@@ -157,6 +157,7 @@ class CheckinListViewSet(viewsets.ModelViewSet):
             list=self.get_object(),
             successful=False,
             forced=True,
+            force_sent=True,
             device=self.request.auth if isinstance(self.request.auth, Device) else None,
             gate=self.request.auth.gate if isinstance(self.request.auth, Device) else None,
             **kwargs,
@@ -424,6 +425,7 @@ class CheckinListPositionViewSet(viewsets.ReadOnlyModelViewSet):
             forced=force,
         )
         raw_barcode_for_checkin = None
+        from_revoked_secret = False
 
         try:
             queryset = self.get_queryset(ignore_status=True, ignore_products=True)
@@ -499,6 +501,7 @@ class CheckinListPositionViewSet(viewsets.ReadOnlyModelViewSet):
             elif revoked_matches and force:
                 op = revoked_matches[0].position
                 raw_barcode_for_checkin = self.kwargs['pk']
+                from_revoked_secret = True
             else:
                 op = revoked_matches[0].position
                 op.order.log_action('pretix.event.checkin.revoked', data={
@@ -550,7 +553,7 @@ class CheckinListPositionViewSet(viewsets.ReadOnlyModelViewSet):
                     auth=self.request.auth,
                     type=type,
                     raw_barcode=raw_barcode_for_checkin,
-                    from_revoked_secret=True,
+                    from_revoked_secret=from_revoked_secret,
                 )
             except RequiredQuestionsError as e:
                 return Response({

src/pretix/api/views/device.py

@@ -42,6 +42,7 @@ class InitializationRequestSerializer(serializers.Serializer):
     hardware_model = serializers.CharField(max_length=190)
     software_brand = serializers.CharField(max_length=190)
     software_version = serializers.CharField(max_length=190)
+    info = serializers.JSONField(required=False, allow_null=True)
 
 
 class UpdateRequestSerializer(serializers.Serializer):
@@ -49,6 +50,7 @@ class UpdateRequestSerializer(serializers.Serializer):
     hardware_model = serializers.CharField(max_length=190)
     software_brand = serializers.CharField(max_length=190)
     software_version = serializers.CharField(max_length=190)
+    info = serializers.JSONField(required=False, allow_null=True)
 
 
 class GateSerializer(serializers.ModelSerializer):
@@ -94,6 +96,7 @@ class InitializeView(APIView):
         device.hardware_model = serializer.validated_data.get('hardware_model')
         device.software_brand = serializer.validated_data.get('software_brand')
         device.software_version = serializer.validated_data.get('software_version')
+        device.info = serializer.validated_data.get('info')
         device.api_token = generate_api_token()
         device.save()
 
@@ -114,6 +117,7 @@ class UpdateView(APIView):
         device.hardware_model = serializer.validated_data.get('hardware_model')
         device.software_brand = serializer.validated_data.get('software_brand')
         device.software_version = serializer.validated_data.get('software_version')
+        device.info = serializer.validated_data.get('info')
         device.save()
         device.log_action('pretix.device.updated', data=serializer.validated_data, auth=device)
 

src/pretix/api/views/discount.py

@@ -0,0 +1,99 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io GmbH and contributors
+#
+# This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General
+# Public License as published by the Free Software Foundation in version 3 of the License.
+#
+# ADDITIONAL TERMS APPLY: Pursuant to Section 7 of the GNU Affero General Public License, additional terms are
+# applicable granting you additional permissions and placing additional restrictions on your usage of this software.
+# Please refer to the pretix LICENSE file to obtain the full terms applicable to this work. If you did not receive
+# this file, see <https://pretix.eu/about/en/license>.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
+# <https://www.gnu.org/licenses/>.
+#
+
+# This file is based on an earlier version of pretix which was released under the Apache License 2.0. The full text of
+# the Apache License 2.0 can be obtained at <http://www.apache.org/licenses/LICENSE-2.0>.
+#
+# This file may have since been changed and any changes are released under the terms of AGPLv3 as described above. A
+# full history of changes and contributors is available at <https://github.com/pretix/pretix>.
+#
+# This file contains Apache-licensed contributions copyrighted by: Ture Gjørup
+#
+# Unless required by applicable law or agreed to in writing, software distributed under the Apache License 2.0 is
+# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations under the License.
+
+from django_filters.rest_framework import DjangoFilterBackend, FilterSet
+from django_scopes import scopes_disabled
+from rest_framework import viewsets
+from rest_framework.exceptions import PermissionDenied
+from rest_framework.filters import OrderingFilter
+
+from pretix.api.serializers.discount import DiscountSerializer
+from pretix.api.views import ConditionalListView
+from pretix.base.models import CartPosition, Discount
+
+with scopes_disabled():
+    class DiscountFilter(FilterSet):
+        class Meta:
+            model = Discount
+            fields = ['active']
+
+
+class DiscountViewSet(ConditionalListView, viewsets.ModelViewSet):
+    serializer_class = DiscountSerializer
+    queryset = Discount.objects.none()
+    filter_backends = (DjangoFilterBackend, OrderingFilter)
+    filterset_class = DiscountFilter
+    ordering_fields = ('id', 'position')
+    ordering = ('position', 'id')
+    permission = None
+    write_permission = 'can_change_items'
+
+    def get_queryset(self):
+        return self.request.event.discounts.all()
+
+    def perform_create(self, serializer):
+        serializer.save(event=self.request.event)
+        serializer.instance.log_action(
+            'pretix.event.discount.added',
+            user=self.request.user,
+            auth=self.request.auth,
+            data=self.request.data
+        )
+
+    def get_serializer_context(self):
+        ctx = super().get_serializer_context()
+        ctx['event'] = self.request.event
+        return ctx
+
+    def perform_update(self, serializer):
+        serializer.save(event=self.request.event)
+        serializer.instance.log_action(
+            'pretix.event.discount.changed',
+            user=self.request.user,
+            auth=self.request.auth,
+            data=self.request.data
+        )
+
+    def perform_destroy(self, instance):
+        if not instance.allow_delete():
+            raise PermissionDenied('You cannot delete this discount because it already has '
+                                   'been used as part of an order.')
+
+        instance.log_action(
+            'pretix.event.discount.deleted',
+            user=self.request.user,
+            auth=self.request.auth,
+        )
+        CartPosition.objects.filter(discount=instance).update(discount=None)
+        super().perform_destroy(instance)

src/pretix/api/views/event.py

@@ -321,6 +321,7 @@ with scopes_disabled():
         is_future = django_filters.rest_framework.BooleanFilter(method='is_future_qs')
         ends_after = django_filters.rest_framework.IsoDateTimeFilter(method='ends_after_qs')
         modified_since = django_filters.IsoDateTimeFilter(field_name='last_modified', lookup_expr='gte')
+        sales_channel = django_filters.rest_framework.CharFilter(method='sales_channel_qs')
 
         class Meta:
             model = SubEvent
@@ -353,6 +354,9 @@ with scopes_disabled():
             else:
                 return queryset.exclude(expr)
 
+        def sales_channel_qs(self, queryset, name, value):
+            return queryset.filter(event__sales_channels__contains=value)
+
 
 class SubEventViewSet(ConditionalListView, viewsets.ModelViewSet):
     serializer_class = SubEventSerializer

src/pretix/api/views/exporters.py

@@ -132,7 +132,7 @@ class EventExportersViewSet(ExportersMixin, viewsets.ViewSet):
     def exporters(self):
         exporters = []
         responses = register_data_exporters.send(self.request.event)
-        for ex in sorted([response(self.request.event, self.request.organizer) for r, response in responses], key=lambda ex: str(ex.verbose_name)):
+        for ex in sorted([response(self.request.event, self.request.organizer) for r, response in responses if response], key=lambda ex: str(ex.verbose_name)):
             ex._serializer = JobRunSerializer(exporter=ex)
             exporters.append(ex)
         return exporters
@@ -147,7 +147,11 @@ class OrganizerExportersViewSet(ExportersMixin, viewsets.ViewSet):
     @cached_property
     def exporters(self):
         exporters = []
-        events = (self.request.auth or self.request.user).get_events_with_permission('can_view_orders', request=self.request).filter(
+        if isinstance(self.request.auth, (Device, TeamAPIToken)):
+            perm_holder = self.request.auth
+        else:
+            perm_holder = self.request.user
+        events = perm_holder.get_events_with_permission('can_view_orders', request=self.request).filter(
             organizer=self.request.organizer
         )
         responses = register_multievent_data_exporters.send(self.request.organizer)
@@ -157,8 +161,12 @@ class OrganizerExportersViewSet(ExportersMixin, viewsets.ViewSet):
         return exporters
 
     def get_serializer_kwargs(self):
+        if isinstance(self.request.auth, (Device, TeamAPIToken)):
+            perm_holder = self.request.auth
+        else:
+            perm_holder = self.request.user
         return {
-            'events': self.request.auth.get_events_with_permission('can_view_orders', request=self.request).filter(
+            'events': perm_holder.get_events_with_permission('can_view_orders', request=self.request).filter(
                 organizer=self.request.organizer
             )
         }

src/pretix/api/views/idempotency.py

@@ -0,0 +1,80 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io GmbH and contributors
+#
+# This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General
+# Public License as published by the Free Software Foundation in version 3 of the License.
+#
+# ADDITIONAL TERMS APPLY: Pursuant to Section 7 of the GNU Affero General Public License, additional terms are
+# applicable granting you additional permissions and placing additional restrictions on your usage of this software.
+# Please refer to the pretix LICENSE file to obtain the full terms applicable to this work. If you did not receive
+# this file, see <https://pretix.eu/about/en/license>.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
+# <https://www.gnu.org/licenses/>.
+#
+import json
+import logging
+from hashlib import sha1
+
+from django.conf import settings
+from django.http import HttpResponse, JsonResponse
+from rest_framework import status
+from rest_framework.views import APIView
+
+from pretix.api.models import ApiCall
+
+logger = logging.getLogger(__name__)
+
+
+class IdempotencyQueryView(APIView):
+    # Experimental feature, therefore undocumented for now
+    authentication_classes = ()
+    permission_classes = ()
+
+    def get(self, request, format=None):
+        idempotency_key = request.GET.get("key")
+        auth_hash_parts = '{}:{}'.format(
+            request.headers.get('Authorization', ''),
+            request.COOKIES.get(settings.SESSION_COOKIE_NAME, '')
+        )
+        auth_hash = sha1(auth_hash_parts.encode()).hexdigest()
+        if not idempotency_key:
+            return JsonResponse({
+                'detail': 'No idempotency key given.'
+            }, status=status.HTTP_404_NOT_FOUND)
+
+        try:
+            call = ApiCall.objects.get(
+                auth_hash=auth_hash,
+                idempotency_key=idempotency_key,
+            )
+        except ApiCall.DoesNotExist:
+            return JsonResponse({
+                'detail': 'Idempotency key not seen before.'
+            }, status=status.HTTP_404_NOT_FOUND)
+
+        if call.locked:
+            r = JsonResponse(
+                {'detail': 'Concurrent request with idempotency key.'},
+                status=status.HTTP_409_CONFLICT,
+            )
+            r['Retry-After'] = 5
+            return r
+
+        content = call.response_body
+        if isinstance(content, memoryview):
+            content = content.tobytes()
+        r = HttpResponse(
+            content=content,
+            status=call.response_code,
+        )
+        for k, v in json.loads(call.response_headers).values():
+            r[k] = v
+        return r

src/pretix/api/views/order.py

@@ -27,7 +27,9 @@ from decimal import Decimal
 import django_filters
 import pytz
 from django.db import transaction
-from django.db.models import Exists, F, OuterRef, Prefetch, Q, Subquery
+from django.db.models import (
+    Exists, F, OuterRef, Prefetch, Q, Subquery, prefetch_related_objects,
+)
 from django.db.models.functions import Coalesce, Concat
 from django.http import FileResponse, HttpResponse
 from django.shortcuts import get_object_or_404
@@ -36,7 +38,7 @@ from django.utils.translation import gettext as _
 from django_filters.rest_framework import DjangoFilterBackend, FilterSet
 from django_scopes import scopes_disabled
 from PIL import Image
-from rest_framework import mixins, serializers, status, viewsets
+from rest_framework import serializers, status, viewsets
 from rest_framework.decorators import action
 from rest_framework.exceptions import (
     APIException, NotFound, PermissionDenied, ValidationError,
@@ -53,6 +55,12 @@ from pretix.api.serializers.order import (
     PriceCalcSerializer, RevokedTicketSecretSerializer,
     SimulatedOrderSerializer,
 )
+from pretix.api.serializers.orderchange import (
+    OrderChangeOperationSerializer, OrderFeeChangeSerializer,
+    OrderPositionChangeSerializer,
+    OrderPositionCreateForExistingOrderSerializer,
+    OrderPositionInfoPatchSerializer,
+)
 from pretix.base.i18n import language
 from pretix.base.models import (
     CachedCombinedTicket, CachedTicket, Checkin, Device, Event, Invoice,
@@ -94,6 +102,7 @@ with scopes_disabled():
         search = django_filters.CharFilter(method='search_qs')
         item = django_filters.CharFilter(field_name='all_positions', lookup_expr='item_id')
         variation = django_filters.CharFilter(field_name='all_positions', lookup_expr='variation_id')
+        subevent = django_filters.CharFilter(field_name='all_positions', lookup_expr='subevent_id')
 
         class Meta:
             model = Order
@@ -143,7 +152,8 @@ with scopes_disabled():
             matching_positions = OrderPosition.objects.filter(
                 Q(order=OuterRef('pk')) & Q(
                     Q(attendee_name_cached__icontains=u) | Q(attendee_email__icontains=u)
-                    | Q(secret__istartswith=u) | Q(voucher__code__icontains=u)
+                    | Q(secret__istartswith=u)
+                    # | Q(voucher__code__icontains=u)  # temporarily removed since it caused bad query performance on postgres
                 )
             ).values('id')
 
@@ -194,37 +204,35 @@ class OrderViewSet(viewsets.ModelViewSet):
         if 'invoice_address' not in self.request.GET.getlist('exclude'):
             qs = qs.select_related('invoice_address')
 
-        if self.request.query_params.get('include_canceled_positions', 'false') == 'true':
+        qs = qs.prefetch_related(self._positions_prefetch(self.request))
+        return qs
+
+    def _positions_prefetch(self, request):
+        if request.query_params.get('include_canceled_positions', 'false') == 'true':
             opq = OrderPosition.all
         else:
             opq = OrderPosition.objects
-        if self.request.query_params.get('pdf_data', 'false') == 'true':
-            qs = qs.prefetch_related(
-                Prefetch(
-                    'positions',
-                    opq.all().prefetch_related(
-                        Prefetch('checkins', queryset=Checkin.objects.all()),
-                        'item', 'variation', 'answers', 'answers__options', 'answers__question',
-                        'item__category', 'addon_to', 'seat',
-                        Prefetch('addons', opq.select_related('item', 'variation', 'seat'))
-                    )
+        if request.query_params.get('pdf_data', 'false') == 'true':
+            return Prefetch(
+                'positions',
+                opq.all().prefetch_related(
+                    Prefetch('checkins', queryset=Checkin.objects.all()),
+                    'item', 'variation', 'answers', 'answers__options', 'answers__question',
+                    'item__category', 'addon_to', 'seat',
+                    Prefetch('addons', opq.select_related('item', 'variation', 'seat'))
                 )
             )
         else:
-            qs = qs.prefetch_related(
-                Prefetch(
-                    'positions',
-                    opq.all().prefetch_related(
-                        Prefetch('checkins', queryset=Checkin.objects.all()),
-                        'item', 'variation',
-                        Prefetch('answers', queryset=QuestionAnswer.objects.prefetch_related('options', 'question').order_by('question__position')),
-                        'seat',
-                    )
+            return Prefetch(
+                'positions',
+                opq.all().prefetch_related(
+                    Prefetch('checkins', queryset=Checkin.objects.all()),
+                    'item', 'variation',
+                    Prefetch('answers', queryset=QuestionAnswer.objects.prefetch_related('options', 'question').order_by('question__position')),
+                    'seat',
                 )
             )
 
-        return qs
-
     def _get_output_provider(self, identifier):
         responses = register_ticket_outputs.send(self.request.event)
         for receiver, response in responses:
@@ -253,8 +261,11 @@ class OrderViewSet(viewsets.ModelViewSet):
         provider = self._get_output_provider(output)
         order = self.get_object()
 
-        if order.status != Order.STATUS_PAID:
-            raise PermissionDenied("Downloads are not available for unpaid orders.")
+        if order.status in (Order.STATUS_CANCELED, Order.STATUS_EXPIRED):
+            raise PermissionDenied("Downloads are not available for canceled or expired orders.")
+
+        if order.status == Order.STATUS_PENDING and not request.event.settings.ticket_download_pending:
+            raise PermissionDenied("Downloads are not available for pending orders.")
 
         ct = CachedCombinedTicket.objects.filter(
             order=order, provider=provider.identifier, file__isnull=False
@@ -337,6 +348,7 @@ class OrderViewSet(viewsets.ModelViewSet):
     @action(detail=True, methods=['POST'])
     def mark_canceled(self, request, **kwargs):
         send_mail = request.data.get('send_email', True)
+        comment = request.data.get('comment', None)
         cancellation_fee = request.data.get('cancellation_fee', None)
         if cancellation_fee:
             try:
@@ -359,6 +371,7 @@ class OrderViewSet(viewsets.ModelViewSet):
                 device=request.auth if isinstance(request.auth, Device) else None,
                 oauth_application=request.auth.application if isinstance(request.auth, OAuthAccessToken) else None,
                 send_mail=send_mail,
+                email_comment=comment,
                 cancellation_fee=cancellation_fee
             )
         except OrderError as e:
@@ -606,6 +619,7 @@ class OrderViewSet(viewsets.ModelViewSet):
                 serializer = SimulatedOrderSerializer(order, context=serializer.context)
                 return Response(serializer.data, status=status.HTTP_201_CREATED)
             else:
+                prefetch_related_objects([order], self._positions_prefetch(request))
                 serializer = OrderSerializer(order, context=serializer.context)
 
             order.log_action(
@@ -643,9 +657,13 @@ class OrderViewSet(viewsets.ModelViewSet):
             if send_mail:
                 free_flow = (
                     payment and order.total == Decimal('0.00') and order.status == Order.STATUS_PAID and
-                    not order.require_approval and payment.provider == "free"
+                    not order.require_approval and payment.provider in ("free", "boxoffice")
                 )
-                if free_flow:
+                if order.require_approval:
+                    email_template = request.event.settings.mail_text_order_placed_require_approval
+                    log_entry = 'pretix.event.order.email.order_placed_require_approval'
+                    email_attendees = False
+                elif free_flow:
                     email_template = request.event.settings.mail_text_order_free
                     log_entry = 'pretix.event.order.email.order_free'
                     email_attendees = request.event.settings.mail_send_order_free_attendee
@@ -658,12 +676,13 @@ class OrderViewSet(viewsets.ModelViewSet):
 
                 _order_placed_email(
                     request.event, order, payment.payment_provider if payment else None, email_template,
-                    log_entry, invoice, payment
+                    log_entry, invoice, payment, is_free=free_flow
                 )
                 if email_attendees:
                     for p in order.positions.all():
                         if p.addon_to_id is None and p.attendee_email and p.attendee_email != order.email:
-                            _order_placed_email_attendee(request.event, order, p, email_attendees_template, log_entry)
+                            _order_placed_email_attendee(request.event, order, p, email_attendees_template, log_entry,
+                                                         is_free=free_flow)
 
                 if not free_flow and order.status == Order.STATUS_PAID and payment:
                     payment._send_paid_mail(invoice, None, '')
@@ -776,6 +795,79 @@ class OrderViewSet(viewsets.ModelViewSet):
         with transaction.atomic():
             self.get_object().gracefully_delete(user=self.request.user if self.request.user.is_authenticated else None, auth=self.request.auth)
 
+    @action(detail=True, methods=['POST'])
+    def change(self, request, **kwargs):
+        order = self.get_object()
+
+        serializer = OrderChangeOperationSerializer(
+            context={'order': order, **self.get_serializer_context()},
+            data=request.data,
+        )
+        serializer.is_valid(raise_exception=True)
+
+        try:
+            ocm = OrderChangeManager(
+                order=order,
+                user=self.request.user if self.request.user.is_authenticated else None,
+                auth=request.auth,
+                notify=serializer.validated_data.get('send_email', False),
+                reissue_invoice=serializer.validated_data.get('reissue_invoice', True),
+            )
+
+            canceled_positions = set()
+            for r in serializer.validated_data.get('cancel_positions', []):
+                ocm.cancel(r['position'])
+                canceled_positions.add(r['position'])
+
+            for r in serializer.validated_data.get('patch_positions', []):
+                if r['position'] in canceled_positions:
+                    continue
+                pos_serializer = OrderPositionChangeSerializer(
+                    context={'ocm': ocm, 'commit': False, 'event': request.event, **self.get_serializer_context()},
+                    partial=True,
+                )
+                pos_serializer.update(r['position'], r['body'])
+
+            for r in serializer.validated_data.get('split_positions', []):
+                if r['position'] in canceled_positions:
+                    continue
+                ocm.split(r['position'])
+
+            for r in serializer.validated_data.get('create_positions', []):
+                pos_serializer = OrderPositionCreateForExistingOrderSerializer(
+                    context={'ocm': ocm, 'commit': False, 'event': request.event, **self.get_serializer_context()},
+                )
+                pos_serializer.create(r)
+
+            canceled_fees = set()
+            for r in serializer.validated_data.get('cancel_fees', []):
+                ocm.cancel_fee(r['fee'])
+                canceled_fees.add(r['fee'])
+
+            for r in serializer.validated_data.get('patch_fees', []):
+                if r['fee'] in canceled_fees:
+                    continue
+                pos_serializer = OrderFeeChangeSerializer(
+                    context={'ocm': ocm, 'commit': False, 'event': request.event, **self.get_serializer_context()},
+                )
+                pos_serializer.update(r['fee'], r['body'])
+
+            if serializer.validated_data.get('recalculate_taxes') == 'keep_net':
+                ocm.recalculate_taxes(keep='net')
+            elif serializer.validated_data.get('recalculate_taxes') == 'keep_gross':
+                ocm.recalculate_taxes(keep='gross')
+
+            ocm.commit()
+        except OrderError as e:
+            raise ValidationError(str(e))
+
+        order.refresh_from_db()
+        serializer = OrderSerializer(
+            instance=order,
+            context=self.get_serializer_context(),
+        )
+        return Response(serializer.data)
+
 
 with scopes_disabled():
     class OrderPositionFilter(FilterSet):
@@ -817,7 +909,7 @@ with scopes_disabled():
             }
 
 
-class OrderPositionViewSet(mixins.DestroyModelMixin, mixins.UpdateModelMixin, viewsets.ReadOnlyModelViewSet):
+class OrderPositionViewSet(viewsets.ModelViewSet):
     serializer_class = OrderPositionSerializer
     queryset = OrderPosition.all.none()
     filter_backends = (DjangoFilterBackend, OrderingFilter)
@@ -1031,8 +1123,11 @@ class OrderPositionViewSet(mixins.DestroyModelMixin, mixins.UpdateModelMixin, vi
         provider = self._get_output_provider(output)
         pos = self.get_object()
 
-        if pos.order.status != Order.STATUS_PAID:
-            raise PermissionDenied("Downloads are not available for unpaid orders.")
+        if pos.order.status in (Order.STATUS_CANCELED, Order.STATUS_EXPIRED):
+            raise PermissionDenied("Downloads are not available for canceled or expired orders.")
+
+        if pos.order.status == Order.STATUS_PENDING and not request.event.settings.ticket_download_pending:
+            raise PermissionDenied("Downloads are not available for pending orders.")
         if not pos.generate_ticket:
             raise PermissionDenied("Downloads are not enabled for this product.")
 
@@ -1054,6 +1149,25 @@ class OrderPositionViewSet(mixins.DestroyModelMixin, mixins.UpdateModelMixin, vi
                 )
                 return resp
 
+    @action(detail=True, methods=['POST'])
+    def regenerate_secrets(self, request, **kwargs):
+        instance = self.get_object()
+        try:
+            ocm = OrderChangeManager(
+                instance.order,
+                user=self.request.user if self.request.user.is_authenticated else None,
+                auth=self.request.auth,
+                notify=False,
+                reissue_invoice=False,
+            )
+            ocm.regenerate_secret(instance)
+            ocm.commit()
+        except OrderError as e:
+            raise ValidationError(str(e))
+        except Quota.QuotaExceededException as e:
+            raise ValidationError(str(e))
+        return self.retrieve(request, [], **kwargs)
+
     def perform_destroy(self, instance):
         try:
             ocm = OrderChangeManager(
@@ -1069,18 +1183,33 @@ class OrderPositionViewSet(mixins.DestroyModelMixin, mixins.UpdateModelMixin, vi
         except Quota.QuotaExceededException as e:
             raise ValidationError(str(e))
 
-    def update(self, request, *args, **kwargs):
-        partial = kwargs.get('partial', False)
-        if not partial:
-            return Response(
-                {"detail": "Method \"PUT\" not allowed."},
-                status=status.HTTP_405_METHOD_NOT_ALLOWED,
-            )
-        return super().update(request, *args, **kwargs)
-
-    def perform_update(self, serializer):
+    def create(self, request, *args, **kwargs):
         with transaction.atomic():
-            old_data = self.get_serializer_class()(instance=serializer.instance, context=self.get_serializer_context()).data
+            serializer = OrderPositionCreateForExistingOrderSerializer(
+                data=request.data,
+                context=self.get_serializer_context(),
+            )
+            serializer.is_valid(raise_exception=True)
+            order = serializer.validated_data['order']
+            ocm = OrderChangeManager(
+                order=order,
+                user=self.request.user if self.request.user.is_authenticated else None,
+                auth=request.auth,
+                notify=False,
+                reissue_invoice=False,
+            )
+            serializer.context['ocm'] = ocm
+            serializer.save()
+
+            # Fields that can be easily patched after the position was added
+            old_data = OrderPositionInfoPatchSerializer(instance=serializer.instance, context=self.get_serializer_context()).data
+            serializer = OrderPositionInfoPatchSerializer(
+                instance=serializer.instance,
+                context=self.get_serializer_context(),
+                partial=True,
+                data=request.data
+            )
+            serializer.is_valid(raise_exception=True)
             serializer.save()
             new_data = serializer.data
 
@@ -1103,9 +1232,77 @@ class OrderPositionViewSet(mixins.DestroyModelMixin, mixins.UpdateModelMixin, vi
                         ]
                     }
                 )
+                tickets.invalidate_cache.apply_async(
+                    kwargs={'event': serializer.instance.order.event.pk, 'order': serializer.instance.order.pk})
+                order_modified.send(sender=serializer.instance.order.event, order=serializer.instance.order)
+        return Response(
+            OrderPositionSerializer(serializer.instance, context=self.get_serializer_context()).data,
+            status=status.HTTP_201_CREATED,
+        )
 
-        tickets.invalidate_cache.apply_async(kwargs={'event': serializer.instance.order.event.pk, 'order': serializer.instance.order.pk})
-        order_modified.send(sender=serializer.instance.order.event, order=serializer.instance.order)
+    def update(self, request, *args, **kwargs):
+        partial = kwargs.get('partial', False)
+        if not partial:
+            return Response(
+                {"detail": "Method \"PUT\" not allowed."},
+                status=status.HTTP_405_METHOD_NOT_ALLOWED,
+            )
+
+        with transaction.atomic():
+            instance = self.get_object()
+            ocm = OrderChangeManager(
+                order=instance.order,
+                user=self.request.user if self.request.user.is_authenticated else None,
+                auth=request.auth,
+                notify=False,
+                reissue_invoice=False,
+            )
+
+            # Field that need to go through OrderChangeManager
+            serializer = OrderPositionChangeSerializer(
+                instance=instance,
+                context={'ocm': ocm, **self.get_serializer_context()},
+                partial=True,
+                data=request.data
+            )
+            serializer.is_valid(raise_exception=True)
+            serializer.save()
+
+            # Fields that can be easily patched
+            old_data = OrderPositionInfoPatchSerializer(instance=instance, context=self.get_serializer_context()).data
+            serializer = OrderPositionInfoPatchSerializer(
+                instance=instance,
+                context=self.get_serializer_context(),
+                partial=True,
+                data=request.data
+            )
+            serializer.is_valid(raise_exception=True)
+            serializer.save()
+            new_data = serializer.data
+
+            if old_data != new_data:
+                log_data = self.request.data
+                if 'answers' in log_data:
+                    for a in new_data['answers']:
+                        log_data[f'question_{a["question"]}'] = a["answer"]
+                    log_data.pop('answers', None)
+                serializer.instance.order.log_action(
+                    'pretix.event.order.modified',
+                    user=self.request.user,
+                    auth=self.request.auth,
+                    data={
+                        'data': [
+                            dict(
+                                position=serializer.instance.pk,
+                                **log_data
+                            )
+                        ]
+                    }
+                )
+                tickets.invalidate_cache.apply_async(kwargs={'event': serializer.instance.order.event.pk, 'order': serializer.instance.order.pk})
+                order_modified.send(sender=serializer.instance.order.event, order=serializer.instance.order)
+
+        return Response(self.get_serializer_class()(instance=serializer.instance, context=self.get_serializer_context()).data)
 
 
 class PaymentViewSet(CreateModelMixin, viewsets.ReadOnlyModelViewSet):

src/pretix/api/views/voucher.py

@@ -25,7 +25,7 @@ from django.db import transaction
 from django.db.models import F, Q
 from django.utils.timezone import now
 from django_filters.rest_framework import (
-    BooleanFilter, DjangoFilterBackend, FilterSet,
+    BooleanFilter, CharFilter, DjangoFilterBackend, FilterSet,
 )
 from django_scopes import scopes_disabled
 from rest_framework import status, viewsets
@@ -40,6 +40,7 @@ from pretix.base.models import Voucher
 with scopes_disabled():
     class VoucherFilter(FilterSet):
         active = BooleanFilter(method='filter_active')
+        code = CharFilter(lookup_expr='iexact')
 
         class Meta:
             model = Voucher

src/pretix/base/auth.py

@@ -94,6 +94,9 @@ class BaseAuthBackend:
         This method will be called after the user filled in the login form. ``request`` will contain
         the current request and ``form_data`` the input for the form fields defined in ``login_form_fields``.
         You are expected to either return a ``User`` object (if login was successful) or ``None``.
+
+        You are expected to either return a ``User`` object (if login was successful) or ``None``. You should
+        obtain this user object using ``User.objects.get_or_create_for_backend``.
         """
         return
 
@@ -104,7 +107,9 @@ class BaseAuthBackend:
         reverse proxy, you can directly return a ``User`` object that will be logged in.
 
         ``request`` will contain the current request.
-        You are expected to either return a ``User`` object (if login was successful) or ``None``.
+
+        You are expected to either return a ``User`` object (if login was successful) or ``None``. You should
+        obtain this user object using ``User.objects.get_or_create_for_backend``.
         """
         return
 
@@ -146,7 +151,8 @@ class NativeAuthBackend(BaseAuthBackend):
         d = OrderedDict([
             ('email', forms.EmailField(label=_("E-mail"), max_length=254,
                                        widget=forms.EmailInput(attrs={'autofocus': 'autofocus'}))),
-            ('password', forms.CharField(label=_("Password"), widget=forms.PasswordInput)),
+            ('password', forms.CharField(label=_("Password"), widget=forms.PasswordInput,
+                                         max_length=4096)),
         ])
         return d
 

src/pretix/base/channels.py

@@ -89,6 +89,13 @@ class SalesChannel:
         """
         return True
 
+    @property
+    def discounts_supported(self) -> bool:
+        """
+        If this property is ``True``, this sales channel can be selected for automatic discounts.
+        """
+        return True
+
 
 def get_all_sales_channels():
     global _ALL_CHANNELS

src/pretix/base/email.py

@@ -25,6 +25,7 @@ from datetime import timedelta
 from decimal import Decimal
 from itertools import groupby
 from smtplib import SMTPResponseException
+from typing import TypeVar
 
 import css_inline
 from django.conf import settings
@@ -32,6 +33,7 @@ from django.core.mail.backends.smtp import EmailBackend
 from django.db.models import Count
 from django.dispatch import receiver
 from django.template.loader import get_template
+from django.utils.formats import date_format
 from django.utils.timezone import now
 from django.utils.translation import (
     get_language, gettext_lazy as _, pgettext_lazy,
@@ -49,23 +51,23 @@ from pretix.base.templatetags.rich_text import markdown_compile_email
 
 logger = logging.getLogger('pretix.base.email')
 
+T = TypeVar("T", bound=EmailBackend)
 
-class CustomSMTPBackend(EmailBackend):
 
-    def test(self, from_addr):
-        try:
-            self.open()
-            self.connection.ehlo_or_helo_if_needed()
-            (code, resp) = self.connection.mail(from_addr, [])
-            if code != 250:
-                logger.warn('Error testing mail settings, code %d, resp: %s' % (code, resp))
-                raise SMTPResponseException(code, resp)
-            (code, resp) = self.connection.rcpt('testdummy@pretix.eu')
-            if (code != 250) and (code != 251):
-                logger.warn('Error testing mail settings, code %d, resp: %s' % (code, resp))
-                raise SMTPResponseException(code, resp)
-        finally:
-            self.close()
+def test_custom_smtp_backend(backend: T, from_addr: str) -> None:
+    try:
+        backend.open()
+        backend.connection.ehlo_or_helo_if_needed()
+        (code, resp) = backend.connection.mail(from_addr, [])
+        if code != 250:
+            logger.warning('Error testing mail settings, code %d, resp: %s' % (code, resp))
+            raise SMTPResponseException(code, resp)
+        (code, resp) = backend.connection.rcpt('testdummy@pretix.eu')
+        if (code != 250) and (code != 251):
+            logger.warning('Error testing mail settings, code %d, resp: %s' % (code, resp))
+            raise SMTPResponseException(code, resp)
+    finally:
+        backend.close()
 
 
 class BaseHTMLMailRenderer:
@@ -163,9 +165,20 @@ class TemplateBasedMailRenderer(BaseHTMLMailRenderer):
                 has_addons=Count('addons')
             ))
             htmlctx['cart'] = [(k, list(v)) for k, v in groupby(
-                positions, key=lambda op: (
-                    op.item, op.variation, op.subevent, op.attendee_name,
-                    (op.pk if op.addon_to_id else None), (op.pk if op.has_addons else None)
+                sorted(
+                    positions,
+                    key=lambda op: (
+                        (op.addon_to.positionid if op.addon_to_id else op.positionid),
+                        op.positionid
+                    )
+                ),
+                key=lambda op: (
+                    op.item,
+                    op.variation,
+                    op.subevent,
+                    op.attendee_name,
+                    op.addon_to_id,
+                    (op.pk if op.has_addons else None)
                 )
             )]
 
@@ -297,7 +310,11 @@ def get_email_context(**kwargs):
             val = [val]
         for v in val:
             if all(rp in kwargs for rp in v.required_context):
-                ctx[v.identifier] = v.render(kwargs)
+                try:
+                    ctx[v.identifier] = v.render(kwargs)
+                except:
+                    ctx[v.identifier] = '(error)'
+                    logger.exception(f'Failed to process email placeholder {v.identifier}.')
     return ctx
 
 
@@ -452,6 +469,15 @@ def base_placeholders(sender, **kwargs):
                 }
             ),
         ),
+        SimpleFunctionalMailTextPlaceholder(
+            'event_location', ['event_or_subevent'], lambda event_or_subevent: str(event_or_subevent.location or ''),
+            lambda event: str(event.location or ''),
+        ),
+        SimpleFunctionalMailTextPlaceholder(
+            'event_admission_time', ['event_or_subevent'],
+            lambda event_or_subevent: date_format(event_or_subevent.date_admission, 'TIME_FORMAT') if event_or_subevent.date_admission else '',
+            lambda event: date_format(event.date_admission, 'TIME_FORMAT') if event.date_admission else '',
+        ),
         SimpleFunctionalMailTextPlaceholder(
             'subevent', ['waiting_list_entry', 'event'],
             lambda waiting_list_entry, event: str(waiting_list_entry.subevent or event),
@@ -621,6 +647,10 @@ def base_placeholders(sender, **kwargs):
             'meta_%s' % k, ['event'], lambda event, k=k: event.meta_data[k],
             v
         ))
+        ph.append(SimpleFunctionalMailTextPlaceholder(
+            'meta_%s' % k, ['event_or_subevent'], lambda event_or_subevent, k=k: event_or_subevent.meta_data[k],
+            v
+        ))
 
     return ph
 

src/pretix/base/exporter.py

@@ -33,7 +33,6 @@
 # License for the specific language governing permissions and limitations under the License.
 
 import io
-import re
 import tempfile
 from collections import OrderedDict, namedtuple
 from decimal import Decimal
@@ -46,26 +45,13 @@ from django.conf import settings
 from django.db.models import QuerySet
 from django.utils.formats import localize
 from django.utils.translation import gettext, gettext_lazy as _
-from openpyxl import Workbook
-from openpyxl.cell.cell import ILLEGAL_CHARACTERS_RE, KNOWN_TYPES, Cell
 
 from pretix.base.models import Event
+from pretix.helpers.safe_openpyxl import (  # NOQA: backwards compatibility for plugins using excel_safe
+    SafeWorkbook, remove_invalid_excel_chars as excel_safe,
+)
 
-
-def excel_safe(val):
-    if isinstance(val, Cell):
-        return val
-
-    if not isinstance(val, KNOWN_TYPES):
-        val = str(val)
-
-    if isinstance(val, bytes):
-        val = val.decode("utf-8", errors="ignore")
-
-    if isinstance(val, str):
-        val = re.sub(ILLEGAL_CHARACTERS_RE, '', val)
-
-    return val
+__ = excel_safe  # just so the compatbility import above is "used" and doesn't get removed by linter
 
 
 class BaseExporter:
@@ -228,7 +214,7 @@ class ListExporter(BaseExporter):
         pass
 
     def _render_xlsx(self, form_data, output_file=None):
-        wb = Workbook(write_only=True)
+        wb = SafeWorkbook(write_only=True)
         ws = wb.create_sheet()
         self.prepare_xlsx_sheet(ws)
         try:
@@ -242,7 +228,7 @@ class ListExporter(BaseExporter):
                 total = line.total
                 continue
             ws.append([
-                excel_safe(val) for val in line
+                val for val in line
             ])
             if total:
                 counter += 1
@@ -347,7 +333,7 @@ class MultiSheetListExporter(ListExporter):
             return self.get_filename() + '.csv', 'text/csv', output.getvalue().encode("utf-8")
 
     def _render_xlsx(self, form_data, output_file=None):
-        wb = Workbook(write_only=True)
+        wb = SafeWorkbook(write_only=True)
         n_sheets = len(self.sheets)
         for i_sheet, (s, l) in enumerate(self.sheets):
             ws = wb.create_sheet(str(l))
@@ -361,8 +347,7 @@ class MultiSheetListExporter(ListExporter):
                     total = line.total
                     continue
                 ws.append([
-                    excel_safe(val)
-                    for val in line
+                    val for val in line
                 ])
                 if total:
                     counter += 1

src/pretix/base/exporters/__init__.py

@@ -21,6 +21,7 @@
 #
 from .answers import *  # noqa
 from .dekodi import *  # noqa
+from .events import *  # noqa
 from .invoices import *  # noqa
 from .json import *  # noqa
 from .mail import *  # noqa

src/pretix/base/exporters/events.py

@@ -0,0 +1,100 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io GmbH and contributors
+#
+# This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General
+# Public License as published by the Free Software Foundation in version 3 of the License.
+#
+# ADDITIONAL TERMS APPLY: Pursuant to Section 7 of the GNU Affero General Public License, additional terms are
+# applicable granting you additional permissions and placing additional restrictions on your usage of this software.
+# Please refer to the pretix LICENSE file to obtain the full terms applicable to this work. If you did not receive
+# this file, see <https://pretix.eu/about/en/license>.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
+# <https://www.gnu.org/licenses/>.
+#
+
+# This file is based on an earlier version of pretix which was released under the Apache License 2.0. The full text of
+# the Apache License 2.0 can be obtained at <http://www.apache.org/licenses/LICENSE-2.0>.
+#
+# This file may have since been changed and any changes are released under the terms of AGPLv3 as described above. A
+# full history of changes and contributors is available at <https://github.com/pretix/pretix>.
+#
+# This file contains Apache-licensed contributions copyrighted by: Tobias Kunze
+#
+# Unless required by applicable law or agreed to in writing, software distributed under the Apache License 2.0 is
+# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations under the License.
+
+from django.dispatch import receiver
+from django.utils.formats import date_format
+from django.utils.functional import cached_property
+from django.utils.translation import gettext_lazy as _
+
+from ...control.forms.filter import get_all_payment_providers
+from ..exporter import ListExporter
+from ..signals import register_multievent_data_exporters
+
+
+class EventDataExporter(ListExporter):
+    identifier = 'eventdata'
+    verbose_name = _('Event data')
+
+    @cached_property
+    def providers(self):
+        return dict(get_all_payment_providers())
+
+    def iterate_list(self, form_data):
+        header = [
+            _("Event name"),
+            _("Short form"),
+            _("Shop is live"),
+            _("Event currency"),
+            _("Event start time"),
+            _("Event end time"),
+            _("Admission time"),
+            _("Start of presale"),
+            _("End of presale"),
+            _("Location"),
+            _("Latitude"),
+            _("Longitude"),
+            _("Internal comment"),
+        ]
+        props = list(self.organizer.meta_properties.all())
+        for p in props:
+            header.append(p.name)
+        yield header
+
+        for e in self.events.all():
+            m = e.meta_data
+            yield [
+                str(e.name),
+                e.slug,
+                _('Yes') if e.live else _('No'),
+                e.currency,
+                date_format(e.date_from, 'SHORT_DATETIME_FORMAT'),
+                date_format(e.date_to, 'SHORT_DATETIME_FORMAT') if e.date_to else '',
+                date_format(e.date_admission, 'SHORT_DATETIME_FORMAT') if e.date_admission else '',
+                date_format(e.presale_start, 'SHORT_DATETIME_FORMAT') if e.presale_start else '',
+                date_format(e.presale_end, 'SHORT_DATETIME_FORMAT') if e.presale_end else '',
+                str(e.location),
+                e.geo_lat or '',
+                e.geo_lon or '',
+                e.comment,
+            ] + [
+                m.get(p.name, '') for p in props
+            ]
+
+    def get_filename(self):
+        return '{}_events'.format(self.events.first().organizer.slug)
+
+
+@receiver(register_multievent_data_exporters, dispatch_uid="multiexporter_eventdata")
+def register_multievent_eventdata_exporter(sender, **kwargs):
+    return EventDataExporter

src/pretix/base/exporters/orderlist.py

@@ -259,7 +259,7 @@ class OrderListExporter(MultiSheetListExporter):
             payment_providers=Subquery(p_providers, output_field=CharField()),
             invoice_numbers=Subquery(i_numbers, output_field=CharField()),
             pcnt=Subquery(s, output_field=IntegerField())
-        ).select_related('invoice_address')
+        ).select_related('invoice_address', 'customer')
 
         qs = self._date_filter(qs, form_data, rel='')
 
@@ -268,8 +268,8 @@ class OrderListExporter(MultiSheetListExporter):
         tax_rates = self._get_all_tax_rates(qs)
 
         headers = [
-            _('Event slug'), _('Order code'), _('Order total'), _('Status'), _('Email'), _('Phone number'), _('Order date'),
-            _('Order time'), _('Company'), _('Name'),
+            _('Event slug'), _('Order code'), _('Order total'), _('Status'), _('Email'), _('Phone number'),
+            _('Order date'), _('Order time'), _('Company'), _('Name'),
         ]
         name_scheme = PERSON_NAME_SCHEMES[self.event.settings.name_scheme] if not self.is_multievent else None
         if name_scheme and len(name_scheme['fields']) > 1:
@@ -294,6 +294,7 @@ class OrderListExporter(MultiSheetListExporter):
         headers.append(_('Follow-up date'))
         headers.append(_('Positions'))
         headers.append(_('E-mail address verified'))
+        headers.append(_('External customer ID'))
         headers.append(_('Payment providers'))
         if form_data.get('include_payment_amounts'):
             payment_methods = self._get_all_payment_methods(qs)
@@ -400,6 +401,7 @@ class OrderListExporter(MultiSheetListExporter):
             row.append(order.custom_followup_at.strftime("%Y-%m-%d") if order.custom_followup_at else "")
             row.append(order.pcnt)
             row.append(_('Yes') if order.email_known_to_work else _('No'))
+            row.append(str(order.customer.external_identifier) if order.customer and order.customer.external_identifier else '')
             row.append(', '.join([
                 str(self.providers.get(p, p)) for p in sorted(set((order.payment_providers or '').split(',')))
                 if p and p != 'free'
@@ -424,13 +426,13 @@ class OrderListExporter(MultiSheetListExporter):
         ).values(
             'm'
         ).order_by()
-        qs = OrderFee.objects.filter(
+        qs = OrderFee.all.filter(
             order__event__in=self.events,
         ).annotate(
             payment_providers=Subquery(p_providers, output_field=CharField()),
-        ).select_related('order', 'order__invoice_address', 'tax_rule')
+        ).select_related('order', 'order__invoice_address', 'order__customer', 'tax_rule')
         if form_data['paid_only']:
-            qs = qs.filter(order__status=Order.STATUS_PAID)
+            qs = qs.filter(order__status=Order.STATUS_PAID, canceled=False)
 
         qs = self._date_filter(qs, form_data, rel='order__')
 
@@ -459,6 +461,7 @@ class OrderListExporter(MultiSheetListExporter):
             _('Address'), _('ZIP code'), _('City'), _('Country'), pgettext('address', 'State'), _('VAT ID'),
         ]
 
+        headers.append(_('External customer ID'))
         headers.append(_('Payment providers'))
         yield headers
 
@@ -469,7 +472,7 @@ class OrderListExporter(MultiSheetListExporter):
             row = [
                 self.event_object_cache[order.event_id].slug,
                 order.code,
-                order.get_status_display(),
+                _("canceled") if op.canceled else order.get_status_display(),
                 order.email,
                 str(order.phone) if order.phone else '',
                 order.datetime.astimezone(tz).strftime('%Y-%m-%d'),
@@ -502,6 +505,7 @@ class OrderListExporter(MultiSheetListExporter):
                 ]
             except InvoiceAddress.DoesNotExist:
                 row += [''] * (8 + (len(name_scheme['fields']) if name_scheme and len(name_scheme['fields']) > 1 else 0))
+            row.append(str(order.customer.external_identifier) if order.customer and order.customer.external_identifier else '')
             row.append(', '.join([
                 str(self.providers.get(p, p)) for p in sorted(set((op.payment_providers or '').split(',')))
                 if p and p != 'free'
@@ -518,19 +522,19 @@ class OrderListExporter(MultiSheetListExporter):
         ).values(
             'm'
         ).order_by()
-        base_qs = OrderPosition.objects.filter(
+        base_qs = OrderPosition.all.filter(
             order__event__in=self.events,
         )
         qs = base_qs.annotate(
             payment_providers=Subquery(p_providers, output_field=CharField()),
         ).select_related(
-            'order', 'order__invoice_address', 'item', 'variation',
+            'order', 'order__invoice_address', 'order__customer', 'item', 'variation',
             'voucher', 'tax_rule'
         ).prefetch_related(
             'answers', 'answers__question', 'answers__options'
         )
         if form_data['paid_only']:
-            qs = qs.filter(order__status=Order.STATUS_PAID)
+            qs = qs.filter(order__status=Order.STATUS_PAID, canceled=False)
 
         qs = self._date_filter(qs, form_data, rel='order__')
 
@@ -573,6 +577,7 @@ class OrderListExporter(MultiSheetListExporter):
             pgettext('address', 'State'),
             _('Voucher'),
             _('Pseudonymization ID'),
+            _('Ticket secret'),
             _('Seat ID'),
             _('Seat name'),
             _('Seat zone'),
@@ -610,6 +615,7 @@ class OrderListExporter(MultiSheetListExporter):
         headers += [
             _('Sales channel'), _('Order locale'),
             _('E-mail address verified'),
+            _('External customer ID'),
             _('Payment providers'),
         ]
 
@@ -627,7 +633,7 @@ class OrderListExporter(MultiSheetListExporter):
                     self.event_object_cache[order.event_id].slug,
                     order.code,
                     op.positionid,
-                    order.get_status_display(),
+                    _("canceled") if op.canceled else order.get_status_display(),
                     order.email,
                     str(order.phone) if order.phone else '',
                     order.datetime.astimezone(tz).strftime('%Y-%m-%d'),
@@ -669,6 +675,7 @@ class OrderListExporter(MultiSheetListExporter):
                     op.state or '',
                     op.voucher.code if op.voucher else '',
                     op.pseudonymization_id,
+                    op.secret,
                 ]
 
                 if op.seat:
@@ -728,7 +735,8 @@ class OrderListExporter(MultiSheetListExporter):
                 row += [
                     order.sales_channel,
                     order.locale,
-                    _('Yes') if order.email_known_to_work else _('No')
+                    _('Yes') if order.email_known_to_work else _('No'),
+                    str(order.customer.external_identifier) if order.customer and order.customer.external_identifier else '',
                 ]
                 row.append(', '.join([
                     str(self.providers.get(p, p)) for p in sorted(set((op.payment_providers or '').split(',')))

src/pretix/base/forms/__init__.py

@@ -38,6 +38,7 @@ import i18nfield.forms
 from django import forms
 from django.forms.models import ModelFormMetaclass
 from django.utils.crypto import get_random_string
+from django.utils.translation import gettext_lazy as _
 from formtools.wizard.views import SessionWizardView
 from hierarkey.forms import HierarkeyForm
 
@@ -112,12 +113,42 @@ class SettingsForm(i18nfield.forms.I18nFormMixin, HierarkeyForm):
             if isinstance(f, (RelativeDateTimeField, RelativeDateField)):
                 f.set_event(self.obj)
 
-    def save(self):
+    def _unmask_secret_fields(self):
         for k, v in self.cleaned_data.items():
             if isinstance(self.fields.get(k), SecretKeySettingsField) and self.cleaned_data.get(k) == SECRET_REDACTED:
                 self.cleaned_data[k] = self.initial[k]
+
+    def save(self):
+        self._unmask_secret_fields()
         return super().save()
 
+    def clean(self):
+        d = super().clean()
+
+        # There is logic in HierarkeyForm.save() to only persist fields that changed. HierarkeyForm determines if
+        # something changed by comparing `self._s.get(name)` to `value`. This leaves an edge case open for multi-lingual
+        # text fields. On the very first load, the initial value in `self._s.get(name)` will be a LazyGettextProxy-based
+        # string. However, only some of the languages are usually visible, so even if the user does not change anything
+        # at all, it will be considered a changed value and stored. We do not want that, as it makes it very hard to add
+        # languages to an organizer/event later on. So we trick it and make sure nothing gets changed in that situation.
+        for name, field in self.fields.items():
+            if isinstance(field, SecretKeySettingsField) and d.get(name) == SECRET_REDACTED and not self.initial.get(name):
+                self.add_error(
+                    name,
+                    _('Due to technical reasons you cannot set inputs, that need to be masked (e.g. passwords), to %(value)s.') % {'value': SECRET_REDACTED}
+                )
+
+            if isinstance(field, i18nfield.forms.I18nFormField):
+                value = d.get(name)
+                if not value:
+                    continue
+
+                current = self._s.get(name, as_type=type(value))
+                if name not in self.changed_data:
+                    d[name] = current
+
+        return d
+
     def get_new_filename(self, name: str) -> str:
         from pretix.base.models import Event
 
@@ -165,10 +196,16 @@ class SecretKeySettingsWidget(forms.TextInput):
         attrs.update({
             'autocomplete': 'new-password'  # see https://bugs.chromium.org/p/chromium/issues/detail?id=370363#c7
         })
+        self.__reflect_value = False
         super().__init__(attrs)
 
+    def value_from_datadict(self, data, files, name):
+        value = super().value_from_datadict(data, files, name)
+        self.__reflect_value = value and value != SECRET_REDACTED
+        return value
+
     def get_context(self, name, value, attrs):
-        if value:
+        if value and not self.__reflect_value:
             value = SECRET_REDACTED
         return super().get_context(name, value, attrs)
 

src/pretix/base/forms/auth.py

@@ -154,6 +154,7 @@ class RegistrationForm(forms.Form):
         widget=forms.PasswordInput(attrs={
             'autocomplete': 'new-password'  # see https://bugs.chromium.org/p/chromium/issues/detail?id=370363#c7
         }),
+        max_length=4096,
         required=True
     )
     password_repeat = forms.CharField(
@@ -161,6 +162,7 @@ class RegistrationForm(forms.Form):
         widget=forms.PasswordInput(attrs={
             'autocomplete': 'new-password'  # see https://bugs.chromium.org/p/chromium/issues/detail?id=370363#c7
         }),
+        max_length=4096,
         required=True
     )
     keep_logged_in = forms.BooleanField(label=_("Keep me logged in"), required=False)
@@ -204,11 +206,13 @@ class PasswordRecoverForm(forms.Form):
     password = forms.CharField(
         label=_('Password'),
         widget=forms.PasswordInput,
+        max_length=4096,
         required=True
     )
     password_repeat = forms.CharField(
         label=_('Repeat password'),
-        widget=forms.PasswordInput
+        widget=forms.PasswordInput,
+        max_length=4096,
     )
 
     def __init__(self, user_id=None, *args, **kwargs):

src/pretix/base/forms/questions.py

@@ -41,16 +41,16 @@ from io import BytesIO
 import dateutil.parser
 import pycountry
 import pytz
-from babel import Locale
 from django import forms
 from django.conf import settings
 from django.contrib import messages
 from django.core.exceptions import ValidationError
 from django.core.files.uploadedfile import SimpleUploadedFile
-from django.core.validators import MaxValueValidator, MinValueValidator
+from django.core.validators import (
+    MaxValueValidator, MinValueValidator, RegexValidator,
+)
 from django.db.models import QuerySet
 from django.forms import Select, widgets
-from django.utils import translation
 from django.utils.formats import date_format
 from django.utils.html import escape
 from django.utils.safestring import mark_safe
@@ -85,7 +85,9 @@ from pretix.base.templatetags.rich_text import rich_text
 from pretix.control.forms import (
     ExtFileField, ExtValidationMixin, SizeValidationMixin, SplitDateTimeField,
 )
-from pretix.helpers.countries import CachedCountries
+from pretix.helpers.countries import (
+    CachedCountries, get_phone_prefixes_sorted_and_localized,
+)
 from pretix.helpers.escapejson import escapejson_attr
 from pretix.helpers.i18n import get_format_without_seconds
 from pretix.presale.signals import question_form_fields
@@ -187,6 +189,15 @@ class NamePartsFormField(forms.MultiValueField):
         defaults = {
             'widget': self.widget,
             'max_length': kwargs.pop('max_length', None),
+            'validators': [
+                RegexValidator(
+                    # The following characters should never appear in a name anywhere of
+                    # the world. However, they commonly appear in inputs generated by spam
+                    # bots.
+                    r'^[^$€/%§{}<>~]*$',
+                    message=_('Please do not use special characters in names.')
+                )
+            ]
         }
         self.scheme_name = kwargs.pop('scheme')
         self.titles = kwargs.pop('titles')
@@ -207,6 +218,7 @@ class NamePartsFormField(forms.MultiValueField):
             if fname == 'title' and self.scheme_titles:
                 d = dict(defaults)
                 d.pop('max_length', None)
+                d.pop('validators', None)
                 field = forms.ChoiceField(
                     **d,
                     choices=[('', '')] + [(d, d) for d in self.scheme_titles[1]]
@@ -215,6 +227,7 @@ class NamePartsFormField(forms.MultiValueField):
             elif fname == 'salutation':
                 d = dict(defaults)
                 d.pop('max_length', None)
+                d.pop('validators', None)
                 field = forms.ChoiceField(
                     **d,
                     choices=[('', '---')] + PERSON_NAME_SALUTATIONS
@@ -240,7 +253,7 @@ class NamePartsFormField(forms.MultiValueField):
         if self.require_all_fields and not all(v for v in value):
             raise forms.ValidationError(self.error_messages['incomplete'], code='required')
 
-        if sum(len(v) for v in value if v) > 250:
+        if sum(len(v) for v in value.values() if v) > 250:
             raise forms.ValidationError(_('Please enter a shorter name.'), code='max_length')
 
         return value
@@ -251,17 +264,14 @@ class WrappedPhonePrefixSelect(Select):
 
     def __init__(self, initial=None):
         choices = [("", "---------")]
-        language = get_babel_locale()  # changed from default implementation that used the django locale
-        locale = Locale(translation.to_locale(language))
-        for prefix, values in _COUNTRY_CODE_TO_REGION_CODE.items():
-            prefix = "+%d" % prefix
-            if initial and initial in values:
-                self.initial = prefix
-            for country_code in values:
-                country_name = locale.territories.get(country_code)
-                if country_name:
-                    choices.append((prefix, "{} {}".format(country_name, prefix)))
-        super().__init__(choices=sorted(choices, key=lambda item: item[1]), attrs={'aria-label': pgettext_lazy('phonenumber', 'International area code')})
+
+        if initial:
+            for prefix, values in _COUNTRY_CODE_TO_REGION_CODE.items():
+                if initial in values:
+                    self.initial = "+%d" % prefix
+                    break
+        choices += get_phone_prefixes_sorted_and_localized()
+        super().__init__(choices=choices, attrs={'aria-label': pgettext_lazy('phonenumber', 'International area code')})
 
     def render(self, name, value, *args, **kwargs):
         return super().render(name, value or self.initial, *args, **kwargs)
@@ -305,7 +315,12 @@ class WrappedPhoneNumberPrefixWidget(PhoneNumberPrefixWidget):
         silently deleting data.
         """
         if value:
-            if type(value) == PhoneNumber:
+            if isinstance(value, str):
+                try:
+                    value = PhoneNumber.from_string(value)
+                except:
+                    pass
+            if isinstance(value, PhoneNumber):
                 if value.country_code and value.national_number:
                     return [
                         "+%d" % value.country_code,
@@ -333,23 +348,41 @@ class WrappedPhoneNumberPrefixWidget(PhoneNumberPrefixWidget):
 def guess_country(event):
     # Try to guess the initial country from either the country of the merchant
     # or the locale. This will hopefully save at least some users some scrolling :)
-    locale = get_language_without_region()
     country = event.settings.region or event.settings.invoice_address_from_country
     if not country:
-        valid_countries = countries.countries
-        if '-' in locale:
-            parts = locale.split('-')
-            # TODO: does this actually work?
-            if parts[1].upper() in valid_countries:
-                country = Country(parts[1].upper())
-            elif parts[0].upper() in valid_countries:
-                country = Country(parts[0].upper())
-        else:
-            if locale.upper() in valid_countries:
-                country = Country(locale.upper())
+        country = get_country_by_locale(get_language_without_region())
     return country
 
 
+def get_country_by_locale(locale):
+    country = None
+    valid_countries = countries.countries
+    if '-' in locale:
+        parts = locale.split('-')
+        # TODO: does this actually work?
+        if parts[1].upper() in valid_countries:
+            country = Country(parts[1].upper())
+        elif parts[0].upper() in valid_countries:
+            country = Country(parts[0].upper())
+    else:
+        if locale.upper() in valid_countries:
+            country = Country(locale.upper())
+    return country
+
+
+def guess_phone_prefix(event):
+    with language(get_babel_locale()):
+        country = str(guess_country(event))
+        return get_phone_prefix(country)
+
+
+def get_phone_prefix(country):
+    for prefix, values in _COUNTRY_CODE_TO_REGION_CODE.items():
+        if country in values:
+            return prefix
+    return None
+
+
 class QuestionCheckboxSelectMultiple(forms.CheckboxSelectMultiple):
     option_template_name = 'pretixbase/forms/widgets/checkbox_option_with_links.html'
 
@@ -396,7 +429,7 @@ class PortraitImageWidget(UploadedFileWidget):
 
     def value_from_datadict(self, data, files, name):
         d = super().value_from_datadict(data, files, name)
-        if d is not None:
+        if d is not None and d is not False:
             d._cropdata = json.loads(data.get(name + '_cropdata', '{}') or '{}')
         return d
 
@@ -674,7 +707,7 @@ class BaseQuestionsForm(forms.Form):
                     label=label, required=required,
                     min_value=q.valid_number_min or Decimal('0.00'),
                     max_value=q.valid_number_max,
-                    help_text=q.help_text,
+                    help_text=help_text,
                     initial=initial.answer if initial else None,
                 )
             elif q.type == Question.TYPE_STRING:
@@ -780,25 +813,26 @@ class BaseQuestionsForm(forms.Form):
                 if q.valid_datetime_max:
                     field.validators.append(MaxDateTimeValidator(q.valid_datetime_max))
             elif q.type == Question.TYPE_PHONENUMBER:
-                with language(get_babel_locale()):
-                    default_country = guess_country(event)
-                    default_prefix = None
-                    for prefix, values in _COUNTRY_CODE_TO_REGION_CODE.items():
-                        if str(default_country) in values:
-                            default_prefix = prefix
+                if initial:
                     try:
-                        initial = PhoneNumber().from_string(initial.answer) if initial else "+{}.".format(default_prefix)
+                        initial = PhoneNumber().from_string(initial.answer)
                     except NumberParseException:
                         initial = None
-                    field = PhoneNumberField(
-                        label=label, required=required,
-                        help_text=help_text,
-                        # We now exploit an implementation detail in PhoneNumberPrefixWidget to allow us to pass just
-                        # a country code but no number as an initial value. It's a bit hacky, but should be stable for
-                        # the future.
-                        initial=initial,
-                        widget=WrappedPhoneNumberPrefixWidget()
-                    )
+
+                if not initial:
+                    phone_prefix = guess_phone_prefix(event)
+                    if phone_prefix:
+                        initial = "+{}.".format(phone_prefix)
+
+                field = PhoneNumberField(
+                    label=label, required=required,
+                    help_text=help_text,
+                    # We now exploit an implementation detail in PhoneNumberPrefixWidget to allow us to pass just
+                    # a country code but no number as an initial value. It's a bit hacky, but should be stable for
+                    # the future.
+                    initial=initial,
+                    widget=WrappedPhoneNumberPrefixWidget()
+                )
             field.question = q
             if answers:
                 # Cache the answer object for later use
@@ -869,6 +903,12 @@ class BaseQuestionsForm(forms.Form):
                 if question_is_required(q) and not answer and answer != 0 and not field.errors:
                     raise ValidationError({'question_%d' % q.pk: [_('This field is required.')]})
 
+        # Strip invisible question from cleaned_data so they don't end up in the database
+        for q in question_cache.values():
+            answer = d.get('question_%d' % q.pk)
+            if q.dependency_question_id and not question_is_visible(q.dependency_question_id, q.dependency_values) and answer is not None:
+                d['question_%d' % q.pk] = None
+
         return d
 
 
@@ -1044,7 +1084,11 @@ class BaseInvoiceAddressForm(forms.ModelForm):
                 self.instance.vat_id_validated = True
                 self.instance.vat_id = normalized_id
             except VATIDFinalError as e:
-                raise ValidationError(e.message)
+                if self.all_optional:
+                    self.instance.vat_id_validated = False
+                    messages.warning(self.request, e.message)
+                else:
+                    raise ValidationError(e.message)
             except VATIDTemporaryError as e:
                 self.instance.vat_id_validated = False
                 if self.request and self.vat_warning:

src/pretix/base/forms/widgets.py

@@ -42,6 +42,24 @@ from django.utils.timezone import get_current_timezone, now
 from django.utils.translation import gettext_lazy as _
 
 
+def replace_arabic_numbers(inp):
+    if not isinstance(inp, str):
+        return inp
+    table = {
+        1632: 48,  # 0
+        1633: 49,  # 1
+        1634: 50,  # 2
+        1635: 51,  # 3
+        1636: 52,  # 4
+        1637: 53,  # 5
+        1638: 54,  # 6
+        1639: 55,  # 7
+        1640: 56,  # 8
+        1641: 57,  # 9
+    }
+    return inp.translate(table)
+
+
 class DatePickerWidget(forms.DateInput):
     def __init__(self, attrs=None, date_format=None):
         attrs = attrs or {}
@@ -62,6 +80,10 @@ class DatePickerWidget(forms.DateInput):
 
         forms.DateInput.__init__(self, date_attrs, date_format)
 
+    def value_from_datadict(self, data, files, name):
+        v = super().value_from_datadict(data, files, name)
+        return replace_arabic_numbers(v)
+
 
 class TimePickerWidget(forms.TimeInput):
     def __init__(self, attrs=None, time_format=None):
@@ -83,17 +105,13 @@ class TimePickerWidget(forms.TimeInput):
 
         forms.TimeInput.__init__(self, time_attrs, time_format)
 
+    def value_from_datadict(self, data, files, name):
+        v = super().value_from_datadict(data, files, name)
+        return replace_arabic_numbers(v)
+
 
 class UploadedFileWidget(forms.ClearableFileInput):
     def __init__(self, *args, **kwargs):
-        # Browsers can't recognize that the server already has a file uploaded
-        # Don't mark this input as being required if we already have an answer
-        # (this needs to be done via the attrs, otherwise we wouldn't get the "required" star on the field label)
-        attrs = kwargs.get('attrs', {})
-        if kwargs.get('required') and kwargs.get('initial'):
-            attrs.update({'required': None})
-        kwargs.update({'attrs': attrs})
-
         self.position = kwargs.pop('position')
         self.event = kwargs.pop('event')
         self.answer = kwargs.pop('answer')
@@ -125,6 +143,15 @@ class UploadedFileWidget(forms.ClearableFileInput):
                     'answer': self.answer.pk,
                 })
 
+    def get_context(self, name, value, attrs):
+        # Browsers can't recognize that the server already has a file uploaded
+        # Don't mark this input as being required if we already have an answer
+        # (this needs to be done via the attrs, otherwise we wouldn't get the "required" star on the field label)
+        ctx = super().get_context(name, value, attrs)
+        if ctx['widget']['is_initial']:
+            ctx['widget']['attrs']['required'] = False
+        return ctx
+
     def format_value(self, value):
         if self.is_initial(value):
             return self.FakeFile(value, self.position, self.event, self.answer)
@@ -178,6 +205,10 @@ class SplitDateTimePickerWidget(forms.SplitDateTimeWidget):
         # Skip one hierarchy level
         forms.MultiWidget.__init__(self, widgets, attrs)
 
+    def value_from_datadict(self, data, files, name):
+        v = super().value_from_datadict(data, files, name)
+        return [replace_arabic_numbers(i) for i in v]
+
 
 class BusinessBooleanRadio(forms.RadioSelect):
     def __init__(self, require_business=False, attrs=None):

src/pretix/base/invoice.py

@@ -510,7 +510,7 @@ class ClassicInvoiceRenderer(BaseReportlabInvoiceRenderer):
         return story
 
     def _get_story(self, doc):
-        has_taxes = any(il.tax_value for il in self.invoice.lines.all())
+        has_taxes = any(il.tax_value for il in self.invoice.lines.all()) or self.invoice.reverse_charge
 
         story = [
             NextPageTemplate('FirstPage'),

src/pretix/base/management/commands/check_order_transactions.py

@@ -23,7 +23,9 @@ from decimal import Decimal
 
 from django.core.management.base import BaseCommand
 from django.db import models
-from django.db.models import Case, F, OuterRef, Q, Subquery, Sum, Value, When
+from django.db.models import (
+    Case, Count, F, OuterRef, Q, Subquery, Sum, Value, When,
+)
 from django.db.models.functions import Coalesce
 from django_scopes import scopes_disabled
 
@@ -45,6 +47,18 @@ class Command(BaseCommand):
                     output_field=models.DecimalField(decimal_places=2, max_digits=10)
                 ), Value(0), output_field=models.DecimalField(decimal_places=2, max_digits=10)
             ),
+            position_cnt=Case(
+                When(Q(status__in=('e', 'c')) | Q(require_approval=True), then=Value(0)),
+                default=Coalesce(
+                    Subquery(
+                        OrderPosition.objects.filter(
+                            order=OuterRef('pk')
+                        ).order_by().values('order').annotate(p=Count('*')).values('p'),
+                        output_field=models.IntegerField()
+                    ), Value(0), output_field=models.IntegerField()
+                ),
+                output_field=models.IntegerField()
+            ),
             fee_total=Coalesce(
                 Subquery(
                     OrderFee.objects.filter(
@@ -61,6 +75,15 @@ class Command(BaseCommand):
                     output_field=models.DecimalField(decimal_places=2, max_digits=10)
                 ), Value(0), output_field=models.DecimalField(decimal_places=2, max_digits=10)
             ),
+            tx_cnt=Coalesce(
+                Subquery(
+                    Transaction.objects.filter(
+                        order=OuterRef('pk'),
+                        item__isnull=False,
+                    ).order_by().values('order').annotate(p=Sum(F('count'))).values('p'),
+                    output_field=models.DecimalField(decimal_places=2, max_digits=10)
+                ), Value(0), output_field=models.DecimalField(decimal_places=2, max_digits=10)
+            ),
         ).annotate(
             correct_total=Case(
                 When(Q(status=Order.STATUS_CANCELED) | Q(status=Order.STATUS_EXPIRED) | Q(require_approval=True),
@@ -70,13 +93,15 @@ class Command(BaseCommand):
             ),
         ).exclude(
             total=F('position_total') + F('fee_total'),
-            tx_total=F('correct_total')
+            tx_total=F('correct_total'),
+            tx_cnt=F('position_cnt')
         ).select_related('event')
         for o in qs:
-            if abs(o.tx_total - o.correct_total) < Decimal('0.00001') and abs(o.position_total + o.fee_total - o.total) < Decimal('0.00001'):
+            if abs(o.tx_total - o.correct_total) < Decimal('0.00001') and abs(o.position_total + o.fee_total - o.total) < Decimal('0.00001') \
+                    and o.tx_cnt == o.position_cnt:
                 # Ignore SQLite which treats Decimals like floats…
                 continue
             print(f"Error in order {o.full_code}: status={o.status}, sum(positions)+sum(fees)={o.position_total + o.fee_total}, "
-                  f"order.total={o.total}, sum(transactions)={o.tx_total}, expected={o.correct_total}")
+                  f"order.total={o.total}, sum(transactions)={o.tx_total}, expected={o.correct_total}, pos_cnt={o.position_cnt}, tx_pos_cnt={o.tx_cnt}")
 
-        self.stderr.write(self.style.SUCCESS(f'Check completed.'))
+        self.stderr.write(self.style.SUCCESS('Check completed.'))

src/pretix/base/management/commands/shell_scoped.py

@@ -19,11 +19,13 @@
 # You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
 # <https://www.gnu.org/licenses/>.
 #
+import logging
 import sys
 
 from django.apps import apps
 from django.core.management import call_command
 from django.core.management.base import BaseCommand
+from django.db import connection
 from django_scopes import scope, scopes_disabled
 
 
@@ -33,6 +35,13 @@ class Command(BaseCommand):
         parser.parse_args = lambda x: parser.parse_known_args(x)[0]
         return parser
 
+    def add_arguments(self, parser):
+        parser.add_argument(
+            '--print-sql',
+            action='store_true',
+            help='Print all SQL queries.',
+        )
+
     def handle(self, *args, **options):
         try:
             from django_extensions.management.commands import shell_plus  # noqa
@@ -41,6 +50,11 @@ class Command(BaseCommand):
             cmd = 'shell'
             del options['skip_checks']
 
+        if options['print_sql']:
+            connection.force_debug_cursor = True
+            logger = logging.getLogger("django.db.backends")
+            logger.setLevel(logging.DEBUG)
+
         parser = self.create_parser(sys.argv[0], sys.argv[1])
         flags = parser.parse_known_args(sys.argv[2:])[1]
         if "--override" in flags:

src/pretix/base/middleware.py

@@ -76,6 +76,10 @@ class LocaleMiddleware(MiddlewareMixin):
                             if lang.startswith(firstpart + '-'):
                                 language = lang
                                 break
+                if language not in settings_holder.settings.locales:
+                    # This seems redundant, but can happen in the rare edge case that settings.locale is (wrongfully)
+                    # not part of settings.locales
+                    language = settings_holder.settings.locales[0]
                 if '-' not in language and settings_holder.settings.region:
                     language += '-' + settings_holder.settings.region
         else:

src/pretix/base/migrations/0102_auto_20181017_0024.py

@@ -4,7 +4,6 @@
 from django.core.exceptions import ImproperlyConfigured
 from django.db import migrations, models
 from django_mysql.checks import mysql_connections
-from django_mysql.utils import connection_is_mariadb
 
 
 def set_attendee_name_parts(apps, schema_editor):
@@ -31,7 +30,7 @@ def check_mysqlversion(apps, schema_editor):
     conns = list(mysql_connections())
     found = 'Unknown version'
     for alias, conn in conns:
-        if connection_is_mariadb(conn) and hasattr(conn, 'mysql_version'):
+        if hasattr(conn, 'mysql_is_mariadb') and conn.mysql_is_mariadb and hasattr(conn, 'mysql_version'):
             if conn.mysql_version >= (10, 2, 7):
                 any_conn_works = True
             else:

src/pretix/base/migrations/0205_itemvariation_require_approval.py

@@ -0,0 +1,18 @@
+# Generated by Django 3.2.9 on 2021-12-13 14:21
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0204_orderposition_backfill_is_bundled'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='itemvariation',
+            name='require_approval',
+            field=models.BooleanField(default=False),
+        ),
+    ]

src/pretix/base/migrations/0206_customer_phone.py

@@ -0,0 +1,19 @@
+# Generated by Django 3.2.9 on 2022-01-12 10:59
+
+import phonenumber_field.modelfields
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0205_itemvariation_require_approval'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='customer',
+            name='phone',
+            field=phonenumber_field.modelfields.PhoneNumberField(max_length=128, null=True, region=None),
+        ),
+    ]

src/pretix/base/migrations/0207_auto_20220119_1427.py

@@ -0,0 +1,23 @@
+# Generated by Django 3.2.4 on 2022-01-19 14:27
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0206_customer_phone'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='taxrule',
+            name='internal_name',
+            field=models.CharField(max_length=190, null=True),
+        ),
+        migrations.AddField(
+            model_name='taxrule',
+            name='keep_gross_if_rate_changes',
+            field=models.BooleanField(default=False),
+        ),
+    ]

src/pretix/base/migrations/0208_auto_20220214_1632.py

@@ -0,0 +1,22 @@
+# Generated by Django 3.2.4 on 2022-02-14 16:32
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0207_auto_20220119_1427'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='user',
+            name='auth_backend_identifier',
+            field=models.CharField(db_index=True, max_length=190, null=True),
+        ),
+        migrations.AlterUniqueTogether(
+            name='user',
+            unique_together={('auth_backend', 'auth_backend_identifier')},
+        ),
+    ]

src/pretix/base/migrations/0209_device_info.py

@@ -0,0 +1,18 @@
+# Generated by Django 3.2.12 on 2022-03-22 11:57
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0208_auto_20220214_1632'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='device',
+            name='info',
+            field=models.JSONField(null=True),
+        ),
+    ]

src/pretix/base/migrations/0210_auto_20220303_2017.py

@@ -0,0 +1,89 @@
+# Generated by Django 3.2.2 on 2022-03-03 20:17
+
+from decimal import Decimal
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+import pretix.base.models.base
+import pretix.base.models.fields
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0209_device_info'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='cartposition',
+            name='custom_price_input',
+            field=models.DecimalField(decimal_places=2, max_digits=10, null=True),
+        ),
+        migrations.AddField(
+            model_name='cartposition',
+            name='custom_price_input_is_net',
+            field=models.BooleanField(default=False),
+        ),
+        migrations.AddField(
+            model_name='cartposition',
+            name='line_price_gross',
+            field=models.DecimalField(decimal_places=2, max_digits=10, null=True),
+        ),
+        migrations.AddField(
+            model_name='cartposition',
+            name='listed_price',
+            field=models.DecimalField(decimal_places=2, max_digits=10, null=True),
+        ),
+        migrations.AddField(
+            model_name='cartposition',
+            name='price_after_voucher',
+            field=models.DecimalField(decimal_places=2, max_digits=10, null=True),
+        ),
+        migrations.AddField(
+            model_name='cartposition',
+            name='tax_rate',
+            field=models.DecimalField(decimal_places=2, default=Decimal('0.00'), max_digits=7),
+        ),
+        migrations.CreateModel(
+            name='Discount',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False)),
+                ('active', models.BooleanField(default=True)),
+                ('internal_name', models.CharField(max_length=255)),
+                ('position', models.PositiveIntegerField(default=0)),
+                ('sales_channels', pretix.base.models.fields.MultiStringField(default=['web'])),
+                ('available_from', models.DateTimeField(blank=True, null=True)),
+                ('available_until', models.DateTimeField(blank=True, null=True)),
+                ('subevent_mode', models.CharField(max_length=50, default='mixed')),
+                ('condition_all_products', models.BooleanField(default=True)),
+                ('condition_min_count', models.PositiveIntegerField(default=0)),
+                ('condition_min_value', models.DecimalField(decimal_places=2, default=Decimal('0.00'), max_digits=10)),
+                ('benefit_discount_matching_percent', models.DecimalField(decimal_places=2, default=Decimal('0.00'), max_digits=10)),
+                ('benefit_only_apply_to_cheapest_n_matches', models.PositiveIntegerField(null=True)),
+                ('condition_limit_products', models.ManyToManyField(to='pretixbase.Item')),
+                ('condition_apply_to_addons', models.BooleanField(default=True)),
+                        ('event', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='discounts', to='pretixbase.event')),
+            ],
+            options={
+                'abstract': False,
+            },
+            bases=(models.Model, pretix.base.models.base.LoggingMixin),
+        ),
+        migrations.AddField(
+            model_name='cartposition',
+            name='discount',
+            field=models.ForeignKey(null=True, on_delete=django.db.models.deletion.RESTRICT, to='pretixbase.discount'),
+        ),
+        migrations.AddField(
+            model_name='orderposition',
+            name='discount',
+            field=models.ForeignKey(null=True, on_delete=django.db.models.deletion.RESTRICT, to='pretixbase.discount'),
+        ),
+        migrations.AddField(
+            model_name='orderposition',
+            name='voucher_budget_use',
+            field=models.DecimalField(decimal_places=2, max_digits=10, null=True),
+        ),
+    ]

src/pretix/base/migrations/0211_auto_20220314_2001.py

@@ -0,0 +1,28 @@
+# Generated by Django 3.2.2 on 2022-03-14 20:01
+from decimal import Decimal
+
+from django.db import migrations
+from django.db.models import F
+from django.db.models.functions import Greatest
+
+
+def migrate_voucher_budget_use(apps, schema_editor):
+    OrderPosition = apps.get_model('pretixbase', 'OrderPosition')  # noqa
+    OrderPosition.all.filter(
+        price_before_voucher__isnull=False
+    ).exclude(price=F('price_before_voucher')).update(
+        voucher_budget_use=Greatest(F('price_before_voucher') - F('price'), Decimal('0.00'))
+    )
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ('pretixbase', '0210_auto_20220303_2017'),
+    ]
+
+    operations = [
+        migrations.RunPython(
+            migrate_voucher_budget_use,
+            migrations.RunPython.noop,
+        ),
+    ]

src/pretix/base/migrations/0212_auto_20220318_1408.py

@@ -0,0 +1,29 @@
+# Generated by Django 3.2.12 on 2022-03-18 14:08
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0211_auto_20220314_2001'),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name='cartposition',
+            name='includes_tax',
+        ),
+        migrations.RemoveField(
+            model_name='cartposition',
+            name='override_tax_rate',
+        ),
+        migrations.RemoveField(
+            model_name='cartposition',
+            name='price_before_voucher',
+        ),
+        migrations.RemoveField(
+            model_name='orderposition',
+            name='price_before_voucher',
+        ),
+    ]

src/pretix/base/migrations/0213_discount_condition_ignore_voucher_discounted.py

@@ -0,0 +1,18 @@
+# Generated by Django 3.2.2 on 2022-04-13 08:24
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0212_auto_20220318_1408'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='discount',
+            name='condition_ignore_voucher_discounted',
+            field=models.BooleanField(default=False),
+        ),
+    ]

src/pretix/base/migrations/0214_customer_notes_ext_id.py

@@ -0,0 +1,23 @@
+# Generated by Django 3.2.12 on 2022-04-28 08:37
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0213_discount_condition_ignore_voucher_discounted'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='customer',
+            name='external_identifier',
+            field=models.CharField(max_length=255, null=True),
+        ),
+        migrations.AddField(
+            model_name='customer',
+            name='notes',
+            field=models.TextField(null=True),
+        ),
+    ]

src/pretix/base/migrations/0215_customer_organizer_identifier_unique.py

@@ -0,0 +1,22 @@
+# Generated by Django 3.2.12 on 2022-05-12 15:34
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0214_customer_notes_ext_id'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='customer',
+            name='identifier',
+            field=models.CharField(db_index=True, max_length=190),
+        ),
+        migrations.AlterUniqueTogether(
+            name='customer',
+            unique_together={('organizer', 'email'), ('organizer', 'identifier')},
+        ),
+    ]

src/pretix/base/migrations/0216_checkin_forced_sent.py

@@ -0,0 +1,18 @@
+# Generated by Django 3.2.12 on 2022-04-29 13:56
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0215_customer_organizer_identifier_unique'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='checkin',
+            name='force_sent',
+            field=models.BooleanField(default=False, null=True),
+        ),
+    ]

src/pretix/base/migrations/0217_eventfooterlink_organizerfooterlink.py

@@ -0,0 +1,33 @@
+# Generated by Django 3.2.12 on 2022-06-15 08:10
+
+import django.db.models.deletion
+import i18nfield.fields
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0216_checkin_forced_sent'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='OrganizerFooterLink',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False)),
+                ('label', i18nfield.fields.I18nCharField(max_length=200)),
+                ('url', models.URLField()),
+                ('organizer', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='footer_links', to='pretixbase.organizer')),
+            ],
+        ),
+        migrations.CreateModel(
+            name='EventFooterLink',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False)),
+                ('label', i18nfield.fields.I18nCharField(max_length=200)),
+                ('url', models.URLField()),
+                ('event', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='footer_links', to='pretixbase.event')),
+            ],
+        ),
+    ]

src/pretix/base/models/__init__.py

@@ -25,6 +25,7 @@ from .base import CachedFile, LoggedModel, cachedfile_name
 from .checkin import Checkin, CheckinList
 from .customers import Customer
 from .devices import Device, Gate
+from .discount import Discount
 from .event import (
     Event, Event_SettingsStore, EventLock, EventMetaProperty, EventMetaValue,
     SubEvent, SubEventMetaValue, generate_invite_token,

src/pretix/base/models/auth.py

@@ -44,7 +44,7 @@ from django.contrib.auth.models import (
 )
 from django.contrib.auth.tokens import default_token_generator
 from django.contrib.contenttypes.models import ContentType
-from django.db import models
+from django.db import IntegrityError, models, transaction
 from django.db.models import Q
 from django.utils.crypto import get_random_string, salted_hmac
 from django.utils.timezone import now
@@ -61,6 +61,10 @@ from pretix.helpers.urls import build_absolute_uri
 from .base import LoggingMixin
 
 
+class EmailAddressTakenError(IntegrityError):
+    pass
+
+
 class UserManager(BaseUserManager):
     """
     This is the user manager for our custom user model. See the User
@@ -83,6 +87,116 @@ class UserManager(BaseUserManager):
         user.save()
         return user
 
+    def get_or_create_for_backend(self, backend, identifier, email, set_always, set_on_creation):
+        """
+        This method should be used by third-party authentication backends to log in a user.
+        It either returns an already existing user or creates a new user.
+
+        In pretix 4.7 and earlier, email addresses were the only property to identify a user with.
+        Starting with pretix 4.8, backends SHOULD instead use a unique, immutable identifier
+        based on their backend data store to allow for changing email addresses.
+
+        This method transparently handles the conversion of old user accounts and adds the
+        backend identifier to their database record.
+
+        This method will never return users managed by a different authentication backend.
+        If you try to create an account with an email address already blocked by a different
+        authentication backend, :py:class:`EmailAddressTakenError` will be raised. In this case,
+        you should display a message to the user.
+
+        :param backend: The `identifier` attribute of the authentication backend
+        :param identifier: The unique, immutable identifier of this user, max. 190 characters
+        :param email: The user's email address
+        :param set_always: A dictionary of fields to update on the user model on every login
+        :param set_on_creation: A dictionary of fields to set on the user model if it's newly created
+        :return: A `User` instance.
+        """
+        if identifier is None:
+            raise ValueError('You need to supply a custom, unique identifier for this user.')
+        if email is None:
+            raise ValueError('You need to supply an email address for this user.')
+        if 'auth_backend_identifier' in set_always or 'auth_backend_identifier' in set_on_creation or \
+                'auth_backend' in set_always or 'auth_backend' in set_on_creation:
+            raise ValueError('You may not update auth_backend/auth_backend_identifier.')
+        if len(identifier) > 190:
+            raise ValueError('The user identifier must not be more than 190 characters.')
+
+        # Always update the email address
+        set_always.update({'email': email})
+
+        # First, check if we find the user based on it's backend-specific authenticator
+        try:
+            u = self.get(
+                auth_backend=backend,
+                auth_backend_identifier=identifier,
+            )
+            dirty = False
+            for k, v in set_always.items():
+                if getattr(u, k) != v:
+                    setattr(u, k, v)
+                    dirty = True
+            if dirty:
+                try:
+                    with transaction.atomic():
+                        u.save(update_fields=set_always.keys())
+                except IntegrityError:
+                    # This might only raise IntegrityError if the email address is used
+                    # by someone else
+                    raise EmailAddressTakenError()
+            return u
+        except self.model.DoesNotExist:
+            pass
+
+        # Second, check if we find the user based on their email address and this backend
+        try:
+            u = self.get(
+                auth_backend=backend,
+                auth_backend_identifier__isnull=True,
+                email=email,
+            )
+            u.auth_backend_identifier = identifier
+            for k, v in set_always.items():
+                setattr(u, k, v)
+            try:
+                with transaction.atomic():
+                    u.save(update_fields=['auth_backend_identifier'] + list(set_always.keys()))
+                return u
+            except IntegrityError:
+                # This might only raise IntegrityError if this code is being executed twice
+                # and runs into a race condition, this mechanism is taken from Django's
+                # get_or_create
+                try:
+                    return self.get(
+                        auth_backend=backend,
+                        auth_backend_identifier=identifier,
+                    )
+                except self.model.DoesNotExist:
+                    pass
+                raise
+        except self.model.DoesNotExist:
+            pass
+
+        # Third, create a new user
+        u = User(
+            auth_backend=backend,
+            auth_backend_identifier=identifier,
+            **set_on_creation,
+            **set_always,
+        )
+        try:
+            u.save(force_insert=True)
+            return u
+        except IntegrityError:
+            # This might either be a race condition or the email address is taken
+            # by a different backend
+            try:
+                return self.get(
+                    auth_backend=backend,
+                    auth_backend_identifier=identifier,
+                )
+            except self.model.DoesNotExist:
+                raise EmailAddressTakenError()
+
 
 def generate_notifications_token():
     return get_random_string(length=32)
@@ -117,6 +231,10 @@ class User(AbstractBaseUser, PermissionsMixin, LoggingMixin):
     :type needs_password_change: bool
     :param timezone: The user's preferred timezone.
     :type timezone: str
+    :param auth_backend: The identifier of the authentication backend plugin responsible for managing this user.
+    :type auth_backend: str
+    :param auth_backend_identifier: The native identifier of the user provided by a non-native authentication backend.
+    :type auth_backend_identifier: str
     """
 
     USERNAME_FIELD = 'email'
@@ -152,6 +270,7 @@ class User(AbstractBaseUser, PermissionsMixin, LoggingMixin):
     )
     notifications_token = models.CharField(max_length=255, default=generate_notifications_token)
     auth_backend = models.CharField(max_length=255, default='native')
+    auth_backend_identifier = models.CharField(max_length=190, db_index=True, null=True, blank=True)
     session_token = models.CharField(max_length=32, default=generate_session_token)
 
     objects = UserManager()
@@ -164,6 +283,7 @@ class User(AbstractBaseUser, PermissionsMixin, LoggingMixin):
         verbose_name = _("User")
         verbose_name_plural = _("Users")
         ordering = ('email',)
+        unique_together = (('auth_backend', 'auth_backend_identifier'),)
 
     def save(self, *args, **kwargs):
         self.email = self.email.lower()
@@ -378,6 +498,23 @@ class User(AbstractBaseUser, PermissionsMixin, LoggingMixin):
             | Q(id__in=self.teams.filter(**kwargs).values_list('limit_events__id', flat=True))
         )
 
+    @scopes_disabled()
+    def get_organizers_with_any_permission(self, request=None):
+        """
+        Returns a queryset of organizers the user has any permissions to.
+
+        :param request: The current request (optional). Required to detect staff sessions properly.
+        :return: Iterable of Organizers
+        """
+        from .event import Organizer
+
+        if request and self.has_active_staff_session(request.session.session_key):
+            return Organizer.objects.all()
+
+        return Organizer.objects.filter(
+            id__in=self.teams.values_list('organizer', flat=True)
+        )
+
     @scopes_disabled()
     def get_organizers_with_permission(self, permission, request=None):
         """

src/pretix/base/models/checkin.py

@@ -188,6 +188,7 @@ class CheckinList(LoggedModel):
         # * in pretix.helpers.jsonlogic_boolalg
         # * in checkinrules.js
         # * in libpretixsync
+        # * in pretixscan-ios (in the future)
         top_level_operators = {
             '<', '<=', '>', '>=', '==', '!=', 'inList', 'isBefore', 'isAfter', 'or', 'and'
         }
@@ -195,7 +196,8 @@ class CheckinList(LoggedModel):
             'buildTime', 'objectList', 'lookup', 'var',
         }
         allowed_vars = {
-            'product', 'variation', 'now', 'entries_number', 'entries_today', 'entries_days'
+            'product', 'variation', 'now', 'now_isoweekday', 'entries_number', 'entries_today', 'entries_days',
+            'minutes_since_last_entry', 'minutes_since_first_entry',
         }
         if not rules or not isinstance(rules, dict):
             return rules
@@ -221,7 +223,7 @@ class CheckinList(LoggedModel):
             return rules
 
         if operator in ('or', 'and') and seen_nonbool:
-            raise ValidationError(f'You cannot use OR/AND logic on a level below a comparison operator.')
+            raise ValidationError('You cannot use OR/AND logic on a level below a comparison operator.')
 
         for v in values:
             cls.validate_rules(v, seen_nonbool=seen_nonbool or operator not in ('or', 'and'), depth=depth + 1)
@@ -324,7 +326,13 @@ class Checkin(models.Model):
     type = models.CharField(max_length=100, choices=CHECKIN_TYPES, default=TYPE_ENTRY)
 
     nonce = models.CharField(max_length=190, null=True, blank=True)
+
+    # Whether or not the scan was made offline
+    force_sent = models.BooleanField(default=False, null=True, blank=True)
+
+    # Whether the scan was made offline AND would have not been possible online
     forced = models.BooleanField(default=False)
+
     device = models.ForeignKey(
         'pretixbase.Device', related_name='checkins', on_delete=models.PROTECT, null=True, blank=True
     )

src/pretix/base/models/customers.py

@@ -24,11 +24,13 @@ from django.conf import settings
 from django.contrib.auth.hashers import (
     check_password, is_password_usable, make_password,
 )
+from django.core.validators import RegexValidator
 from django.db import models
 from django.db.models import F, Q
 from django.utils.crypto import get_random_string, salted_hmac
 from django.utils.translation import gettext_lazy as _, pgettext_lazy
 from django_scopes import ScopedManager, scopes_disabled
+from phonenumber_field.modelfields import PhoneNumberField
 
 from pretix.base.banlist import banned
 from pretix.base.models.base import LoggedModel
@@ -43,8 +45,20 @@ class Customer(LoggedModel):
     """
     id = models.BigAutoField(primary_key=True)
     organizer = models.ForeignKey(Organizer, related_name='customers', on_delete=models.CASCADE)
-    identifier = models.CharField(max_length=190, db_index=True, unique=True)
+    identifier = models.CharField(
+        max_length=190,
+        db_index=True,
+        help_text=_('You can enter any value here to make it easier to match the data with other sources. If you do '
+                    'not input one, we will generate one automatically.'),
+        validators=[
+            RegexValidator(
+                regex=r"^[a-zA-Z0-9]([a-zA-Z0-9.\-_]*[a-zA-Z0-9])?$",
+                message=_("The identifier may only contain letters, numbers, dots, dashes, and underscores. It must start and end with a letter or number."),
+            ),
+        ],
+    )
     email = models.EmailField(db_index=True, null=True, blank=False, verbose_name=_('E-mail'), max_length=190)
+    phone = PhoneNumberField(null=True, blank=True, verbose_name=_('Phone number'))
     password = models.CharField(verbose_name=_('Password'), max_length=128)
     name_cached = models.CharField(max_length=255, verbose_name=_('Full name'), blank=True)
     name_parts = models.JSONField(default=dict)
@@ -57,11 +71,13 @@ class Customer(LoggedModel):
                               default=settings.LANGUAGE_CODE,
                               verbose_name=_('Language'))
     last_modified = models.DateTimeField(auto_now=True)
+    external_identifier = models.CharField(max_length=255, verbose_name=_('External identifier'), null=True, blank=True)
+    notes = models.TextField(verbose_name=_('Notes'), null=True, blank=True)
 
     objects = ScopedManager(organizer='organizer')
 
     class Meta:
-        unique_together = [['organizer', 'email']]
+        unique_together = [['organizer', 'email'], ['organizer', 'identifier']]
         ordering = ('email',)
 
     def get_email_field_name(self):
@@ -87,6 +103,9 @@ class Customer(LoggedModel):
         self.name_parts = {}
         self.name_cached = ''
         self.email = None
+        self.phone = None
+        self.external_identifier = None
+        self.notes = None
         self.save()
         self.all_logentries().update(data={}, shredded=True)
         self.orders.all().update(customer=None)
@@ -169,6 +188,7 @@ class Customer(LoggedModel):
         return salted_hmac(key_salt, payload).hexdigest()
 
     def get_email_context(self):
+        from pretix.base.email import get_name_parts_localized
         ctx = {
             'name': self.name,
             'organizer': self.organizer.name,
@@ -177,7 +197,13 @@ class Customer(LoggedModel):
         for f, l, w in name_scheme['fields']:
             if f == 'full_name':
                 continue
-            ctx['name_%s' % f] = self.name_parts.get(f, '')
+            ctx['name_%s' % f] = get_name_parts_localized(self.name_parts, f)
+
+        if "concatenation_for_salutation" in name_scheme:
+            ctx['name_for_salutation'] = name_scheme["concatenation_for_salutation"](self.name_parts)
+        else:
+            ctx['name_for_salutation'] = name_scheme["concatenation"](self.name_parts)
+
         return ctx
 
     @property

src/pretix/base/models/devices.py

@@ -156,6 +156,9 @@ class Device(LoggedModel):
         null=True,
         blank=False
     )
+    info = models.JSONField(
+        null=True, blank=True,
+    )
 
     objects = ScopedManager(organizer='organizer')
 
@@ -176,6 +179,7 @@ class Device(LoggedModel):
         return {
             'can_view_orders',
             'can_change_orders',
+            'can_view_vouchers',
             'can_manage_gift_cards'
         }
 

src/pretix/base/models/discount.py

@@ -0,0 +1,368 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io GmbH and contributors
+#
+# This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General
+# Public License as published by the Free Software Foundation in version 3 of the License.
+#
+# ADDITIONAL TERMS APPLY: Pursuant to Section 7 of the GNU Affero General Public License, additional terms are
+# applicable granting you additional permissions and placing additional restrictions on your usage of this software.
+# Please refer to the pretix LICENSE file to obtain the full terms applicable to this work. If you did not receive
+# this file, see <https://pretix.eu/about/en/license>.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
+# <https://www.gnu.org/licenses/>.
+#
+
+from collections import defaultdict
+from decimal import Decimal
+from itertools import groupby
+from typing import Dict, Optional, Tuple
+
+from django.core.exceptions import ValidationError
+from django.core.validators import MinValueValidator
+from django.db import models
+from django.utils.translation import gettext_lazy as _, pgettext_lazy
+from django_scopes import ScopedManager
+
+from pretix.base.decimal import round_decimal
+from pretix.base.models import fields
+from pretix.base.models.base import LoggedModel
+
+
+class Discount(LoggedModel):
+    SUBEVENT_MODE_MIXED = 'mixed'
+    SUBEVENT_MODE_SAME = 'same'
+    SUBEVENT_MODE_DISTINCT = 'distinct'
+    SUBEVENT_MODE_CHOICES = (
+        (SUBEVENT_MODE_MIXED, pgettext_lazy('subevent', 'Dates can be mixed without limitation')),
+        (SUBEVENT_MODE_SAME, pgettext_lazy('subevent', 'All matching products must be for the same date')),
+        (SUBEVENT_MODE_DISTINCT, pgettext_lazy('subevent', 'Each matching product must be for a different date')),
+    )
+
+    event = models.ForeignKey(
+        'Event',
+        on_delete=models.CASCADE,
+        related_name='discounts',
+    )
+    active = models.BooleanField(
+        verbose_name=_("Active"),
+        default=True,
+    )
+    internal_name = models.CharField(
+        verbose_name=_("Internal name"),
+        max_length=255
+    )
+    position = models.PositiveIntegerField(
+        default=0,
+        verbose_name=_("Position")
+    )
+    sales_channels = fields.MultiStringField(
+        verbose_name=_('Sales channels'),
+        default=['web'],
+        blank=False,
+    )
+
+    available_from = models.DateTimeField(
+        verbose_name=_("Available from"),
+        null=True,
+        blank=True,
+    )
+    available_until = models.DateTimeField(
+        verbose_name=_("Available until"),
+        null=True,
+        blank=True,
+    )
+
+    subevent_mode = models.CharField(
+        verbose_name=_('Event series handling'),
+        max_length=50,
+        default=SUBEVENT_MODE_MIXED,
+        choices=SUBEVENT_MODE_CHOICES,
+    )
+
+    condition_all_products = models.BooleanField(
+        default=True,
+        verbose_name=_("Apply to all products (including newly created ones)")
+    )
+    condition_limit_products = models.ManyToManyField(
+        'Item',
+        verbose_name=_("Apply to specific products"),
+        blank=True
+    )
+    condition_apply_to_addons = models.BooleanField(
+        default=True,
+        verbose_name=_("Apply to add-on products"),
+        help_text=_("Discounts never apply to bundled products"),
+    )
+    condition_ignore_voucher_discounted = models.BooleanField(
+        default=False,
+        verbose_name=_("Ignore products discounted by a voucher"),
+        help_text=_("If this option is checked, products that already received a discount through a voucher will not "
+                    "be considered for this discount. However, products that use a voucher only to e.g. unlock a "
+                    "hidden product or gain access to sold-out quota will still receive the discount."),
+    )
+    condition_min_count = models.PositiveIntegerField(
+        verbose_name=_('Minimum number of matching products'),
+        default=0,
+    )
+    condition_min_value = models.DecimalField(
+        verbose_name=_('Minimum gross value of matching products'),
+        decimal_places=2,
+        max_digits=10,
+        default=Decimal('0.00'),
+    )
+
+    benefit_discount_matching_percent = models.DecimalField(
+        verbose_name=_('Percentual discount on matching products'),
+        decimal_places=2,
+        max_digits=10,
+        default=Decimal('0.00'),
+        validators=[MinValueValidator(Decimal('0.00'))],
+    )
+    benefit_only_apply_to_cheapest_n_matches = models.PositiveIntegerField(
+        verbose_name=_('Apply discount only to this number of matching products'),
+        help_text=_(
+            'This option allows you to create discounts of the type "buy X get Y reduced/for free". For example, if '
+            'you set "Minimum number of matching products" to four and this value to two, the customer\'s cart will be '
+            'split into groups of four tickets and the cheapest two tickets within every group will be discounted. If '
+            'you want to grant the discount on all matching products, keep this field empty.'
+        ),
+        null=True,
+        blank=True,
+        validators=[MinValueValidator(1)],
+    )
+
+    # more feature ideas:
+    # - max_usages_per_order
+    # - promote_to_user_if_almost_satisfied
+    # - require_customer_account
+
+    objects = ScopedManager(organizer='event__organizer')
+
+    class Meta:
+        ordering = ('position', 'id')
+
+    def __str__(self):
+        return self.internal_name
+
+    @property
+    def sortkey(self):
+        return self.position, self.id
+
+    def __lt__(self, other) -> bool:
+        return self.sortkey < other.sortkey
+
+    @classmethod
+    def validate_config(cls, data):
+        # We forbid a few combinations of settings, because we don't think they are neccessary and at the same
+        # time they introduce edge cases, in which it becomes almost impossible to compute the discount optimally
+        # and also very hard to understand for the user what is going on.
+        if data.get('condition_min_count') and data.get('condition_min_value'):
+            raise ValidationError(
+                _('You can either set a minimum number of matching products or a minimum value, not both.')
+            )
+
+        if not data.get('condition_min_count') and not data.get('condition_min_value'):
+            raise ValidationError(
+                _('You need to either set a minimum number of matching products or a minimum value.')
+            )
+
+        if data.get('condition_min_value') and data.get('benefit_only_apply_to_cheapest_n_matches'):
+            raise ValidationError(
+                _('You cannot apply the discount only to some of the matched products if you are matching '
+                  'on a minimum value.')
+            )
+
+        if data.get('subevent_mode') == cls.SUBEVENT_MODE_DISTINCT and data.get('condition_min_value'):
+            raise ValidationError(
+                _('You cannot apply the discount only to bookings of different dates if you are matching '
+                  'on a minimum value.')
+            )
+
+    def allow_delete(self):
+        return not self.orderposition_set.exists()
+
+    def clean(self):
+        super().clean()
+        Discount.validate_config({
+            'condition_min_count': self.condition_min_count,
+            'condition_min_value': self.condition_min_value,
+            'benefit_only_apply_to_cheapest_n_matches': self.benefit_only_apply_to_cheapest_n_matches,
+            'subevent_mode': self.subevent_mode,
+        })
+
+    def _apply_min_value(self, positions, idx_group, result):
+        if self.condition_min_value and sum(positions[idx][2] for idx in idx_group) < self.condition_min_value:
+            return
+
+        if self.condition_min_count or self.benefit_only_apply_to_cheapest_n_matches:
+            raise ValueError('Validation invariant violated.')
+
+        for idx in idx_group:
+            previous_price = positions[idx][2]
+            new_price = round_decimal(
+                previous_price * (Decimal('100.00') - self.benefit_discount_matching_percent) / Decimal('100.00'),
+                self.event.currency,
+            )
+            result[idx] = new_price
+
+    def _apply_min_count(self, positions, idx_group, result):
+        if len(idx_group) < self.condition_min_count:
+            return
+
+        if not self.condition_min_count or self.condition_min_value:
+            raise ValueError('Validation invariant violated.')
+
+        if self.benefit_only_apply_to_cheapest_n_matches:
+            if not self.condition_min_count:
+                raise ValueError('Validation invariant violated.')
+
+            idx_group = sorted(idx_group, key=lambda idx: (positions[idx][2], -idx))  # sort by line_price
+
+            # Prevent over-consuming of items, i.e. if our discount is "buy 2, get 1 free", we only
+            # want to match multiples of 3
+            consume_idx = idx_group[:len(idx_group) // self.condition_min_count * self.condition_min_count]
+            benefit_idx = idx_group[:len(idx_group) // self.condition_min_count * self.benefit_only_apply_to_cheapest_n_matches]
+        else:
+            consume_idx = idx_group
+            benefit_idx = idx_group
+
+        for idx in benefit_idx:
+            previous_price = positions[idx][2]
+            new_price = round_decimal(
+                previous_price * (Decimal('100.00') - self.benefit_discount_matching_percent) / Decimal('100.00'),
+                self.event.currency,
+            )
+            result[idx] = new_price
+
+        for idx in consume_idx:
+            result.setdefault(idx, positions[idx][2])
+
+    def apply(self, positions: Dict[int, Tuple[int, Optional[int], Decimal, bool, Decimal]]) -> Dict[int, Decimal]:
+        """
+        Tries to apply this discount to a cart
+
+        :param positions: Dictionary mapping IDs to tuples of the form
+                          ``(item_id, subevent_id, line_price_gross, is_addon_to, voucher_discount)``.
+                          Bundled positions may not be included.
+
+        :return: A dictionary mapping keys from the input dictionary to new prices. All positions
+                 contained in this dictionary are considered "consumed" and should not be considered
+                 by other discounts.
+        """
+        result = {}
+
+        if not self.active:
+            return result
+
+        limit_products = set()
+        if not self.condition_all_products:
+            limit_products = {p.pk for p in self.condition_limit_products.all()}
+
+        # First, filter out everything not even covered by our product scope
+        initial_candidates = [
+            idx
+            for idx, (item_id, subevent_id, line_price_gross, is_addon_to, voucher_discount) in positions.items()
+            if (
+                (self.condition_all_products or item_id in limit_products) and
+                (self.condition_apply_to_addons or not is_addon_to) and
+                (not self.condition_ignore_voucher_discounted or voucher_discount is None or voucher_discount == Decimal('0.00'))
+            )
+        ]
+
+        if self.subevent_mode == self.SUBEVENT_MODE_MIXED:  # also applies to non-series events
+            if self.condition_min_count:
+                self._apply_min_count(positions, initial_candidates, result)
+            else:
+                self._apply_min_value(positions, initial_candidates, result)
+
+        elif self.subevent_mode == self.SUBEVENT_MODE_SAME:
+            def key(idx):
+                return positions[idx][1]  # subevent_id
+
+            # Build groups of candidates with the same subevent, then apply our regular algorithm
+            # to each group
+
+            _groups = groupby(sorted(initial_candidates, key=key), key=key)
+            candidate_groups = [list(g) for k, g in _groups]
+
+            for g in candidate_groups:
+                if self.condition_min_count:
+                    self._apply_min_count(positions, g, result)
+                else:
+                    self._apply_min_value(positions, g, result)
+
+        elif self.subevent_mode == self.SUBEVENT_MODE_DISTINCT:
+            if self.condition_min_value:
+                raise ValueError('Validation invariant violated.')
+
+            # Build optimal groups of candidates with distinct subevents, then apply our regular algorithm
+            # to each group. Optimal, in this case, means:
+            # - First try to build as many groups of size condition_min_count as possible while trying to
+            #   balance out the cheapest products so that they are not all in the same group
+            # - Then add remaining positions to existing groups if possible
+            candidate_groups = []
+
+            # Build a list of subevent IDs in descending order of frequency
+            subevent_to_idx = defaultdict(list)
+            for idx, p in positions.items():
+                subevent_to_idx[p[1]].append(idx)
+            for v in subevent_to_idx.values():
+                v.sort(key=lambda idx: positions[idx][2])
+            subevent_order = sorted(list(subevent_to_idx.keys()), key=lambda s: len(subevent_to_idx[s]), reverse=True)
+
+            # Build groups of exactly condition_min_count distinct subevents
+            current_group = []
+            while True:
+                # Build a list of candidates, which is a list of all positions belonging to a subevent of the
+                # maximum cardinality, where the cardinality of a subevent is defined as the number of tickets
+                # for that subevent that are not yet part of any group
+                candidates = []
+                cardinality = None
+                for se, l in subevent_to_idx.items():
+                    l = [ll for ll in l if ll not in current_group]
+                    if cardinality and len(l) != cardinality:
+                        continue
+                    if se not in {positions[idx][1] for idx in current_group}:
+                        candidates += l
+                        cardinality = len(l)
+
+                if not candidates:
+                    break
+
+                # Sort the list by prices, then pick one. For "buy 2 get 1 free" we apply a "pick 1 from the start
+                # and 2 from the end" scheme to optimize price distribution among groups
+                candidates = sorted(candidates, key=lambda idx: positions[idx][2])
+                if len(current_group) < (self.benefit_only_apply_to_cheapest_n_matches or 0):
+                    candidate = candidates[0]
+                else:
+                    candidate = candidates[-1]
+
+                current_group.append(candidate)
+
+                # Only add full groups to the list of groups
+                if len(current_group) >= max(self.condition_min_count, 1):
+                    candidate_groups.append(current_group)
+                    for c in current_group:
+                        subevent_to_idx[positions[c][1]].remove(c)
+                    current_group = []
+
+            # Distribute "leftovers"
+            for se in subevent_order:
+                if subevent_to_idx[se]:
+                    for group in candidate_groups:
+                        if se not in {positions[idx][1] for idx in group}:
+                            group.append(subevent_to_idx[se].pop())
+                            if not subevent_to_idx[se]:
+                                break
+
+            for g in candidate_groups:
+                self._apply_min_count(positions, g, result)
+        return result

src/pretix/base/models/event.py

@@ -608,11 +608,14 @@ class Event(EventMixin, LoggedModel):
             return super().presale_has_ended
 
     def delete_all_orders(self, really=False):
-        from .orders import OrderFee, OrderPayment, OrderPosition, OrderRefund
+        from .orders import (
+            OrderFee, OrderPayment, OrderPosition, OrderRefund, Transaction,
+        )
 
         if not really:
             raise TypeError("Pass really=True as a parameter.")
 
+        Transaction.objects.filter(order__event=self).delete()
         OrderPosition.all.filter(order__event=self, addon_to__isnull=False).delete()
         OrderPosition.all.filter(order__event=self).delete()
         OrderFee.objects.filter(order__event=self).delete()
@@ -665,21 +668,22 @@ class Event(EventMixin, LoggedModel):
 
         return locking.LockManager(self)
 
-    def get_mail_backend(self, timeout=None, force_custom=False):
+    def get_mail_backend(self, timeout=None):
         """
         Returns an email server connection, either by using the system-wide connection
         or by returning a custom one based on the event's settings.
         """
-        from pretix.base.email import CustomSMTPBackend
 
-        if self.settings.smtp_use_custom or force_custom:
-            return CustomSMTPBackend(host=self.settings.smtp_host,
-                                     port=self.settings.smtp_port,
-                                     username=self.settings.smtp_username,
-                                     password=self.settings.smtp_password,
-                                     use_tls=self.settings.smtp_use_tls,
-                                     use_ssl=self.settings.smtp_use_ssl,
-                                     fail_silently=False, timeout=timeout)
+        if self.settings.smtp_use_custom:
+            return get_connection(backend=settings.EMAIL_CUSTOM_SMTP_BACKEND,
+                                  host=self.settings.smtp_host,
+                                  port=self.settings.smtp_port,
+                                  username=self.settings.smtp_username,
+                                  password=self.settings.smtp_password,
+                                  use_tls=self.settings.smtp_use_tls,
+                                  use_ssl=self.settings.smtp_use_ssl,
+                                  fail_silently=False,
+                                  timeout=timeout)
         else:
             return get_connection(fail_silently=False)
 
@@ -699,8 +703,8 @@ class Event(EventMixin, LoggedModel):
 
         from ..signals import event_copy_data
         from . import (
-            Item, ItemAddOn, ItemBundle, ItemCategory, ItemMetaValue, Question,
-            Quota,
+            Discount, Item, ItemAddOn, ItemBundle, ItemCategory, ItemMetaValue,
+            Question, Quota,
         )
 
         #  Note: avoid self.set_active_plugins(), it causes trouble e.g. for the badges plugin.
@@ -717,12 +721,17 @@ class Event(EventMixin, LoggedModel):
         self.save()
         self.log_action('pretix.object.cloned', data={'source': other.slug, 'source_id': other.pk})
 
+        for fl in EventFooterLink.objects.filter(event=other):
+            fl.pk = None
+            fl.event = self
+            fl.save(force_insert=True)
+
         tax_map = {}
         for t in other.tax_rules.all():
             tax_map[t.pk] = t
             t.pk = None
             t.event = self
-            t.save()
+            t.save(force_insert=True)
             t.log_action('pretix.object.cloned')
 
         category_map = {}
@@ -730,7 +739,7 @@ class Event(EventMixin, LoggedModel):
             category_map[c.pk] = c
             c.pk = None
             c.event = self
-            c.save()
+            c.save(force_insert=True)
             c.log_action('pretix.object.cloned')
 
         item_meta_properties_map = {}
@@ -738,7 +747,7 @@ class Event(EventMixin, LoggedModel):
             item_meta_properties_map[imp.pk] = imp
             imp.pk = None
             imp.event = self
-            imp.save()
+            imp.save(force_insert=True)
             imp.log_action('pretix.object.cloned')
 
         item_map = {}
@@ -759,7 +768,7 @@ class Event(EventMixin, LoggedModel):
             if i.grant_membership_type and other.organizer_id != self.organizer_id:
                 i.grant_membership_type = None
 
-            i.save()
+            i.save()  # no force_insert since i.picture.save could have already inserted
             i.log_action('pretix.object.cloned')
 
             if require_membership_types and other.organizer_id == self.organizer_id:
@@ -769,19 +778,19 @@ class Event(EventMixin, LoggedModel):
                 variation_map[v.pk] = v
                 v.pk = None
                 v.item = i
-                v.save()
+                v.save(force_insert=True)
 
         for imv in ItemMetaValue.objects.filter(item__event=other).prefetch_related('item', 'property'):
             imv.pk = None
             imv.property = item_meta_properties_map[imv.property.pk]
             imv.item = item_map[imv.item.pk]
-            imv.save()
+            imv.save(force_insert=True)
 
         for ia in ItemAddOn.objects.filter(base_item__event=other).prefetch_related('base_item', 'addon_category'):
             ia.pk = None
             ia.base_item = item_map[ia.base_item.pk]
             ia.addon_category = category_map[ia.addon_category.pk]
-            ia.save()
+            ia.save(force_insert=True)
 
         for ia in ItemBundle.objects.filter(base_item__event=other).prefetch_related('base_item', 'bundled_item', 'bundled_variation'):
             ia.pk = None
@@ -789,7 +798,7 @@ class Event(EventMixin, LoggedModel):
             ia.bundled_item = item_map[ia.bundled_item.pk]
             if ia.bundled_variation:
                 ia.bundled_variation = variation_map[ia.bundled_variation.pk]
-            ia.save()
+            ia.save(force_insert=True)
 
         quota_map = {}
         for q in Quota.objects.filter(event=other, subevent__isnull=True).prefetch_related('items', 'variations'):
@@ -800,7 +809,7 @@ class Event(EventMixin, LoggedModel):
             q.pk = None
             q.event = self
             q.closed = False
-            q.save()
+            q.save(force_insert=True)
             q.log_action('pretix.object.cloned')
             for i in items:
                 if i.pk in item_map:
@@ -809,6 +818,16 @@ class Event(EventMixin, LoggedModel):
                 q.variations.add(variation_map[v.pk])
             self.items.filter(hidden_if_available_id=oldid).update(hidden_if_available=q)
 
+        for d in Discount.objects.filter(event=other).prefetch_related('condition_limit_products'):
+            items = list(d.condition_limit_products.all())
+            d.pk = None
+            d.event = self
+            d.save(force_insert=True)
+            d.log_action('pretix.object.cloned')
+            for i in items:
+                if i.pk in item_map:
+                    d.condition_limit_products.add(item_map[i.pk])
+
         question_map = {}
         for q in Question.objects.filter(event=other).prefetch_related('items', 'options'):
             items = list(q.items.all())
@@ -816,7 +835,7 @@ class Event(EventMixin, LoggedModel):
             question_map[q.pk] = q
             q.pk = None
             q.event = self
-            q.save()
+            q.save(force_insert=True)
             q.log_action('pretix.object.cloned')
 
             for i in items:
@@ -824,7 +843,7 @@ class Event(EventMixin, LoggedModel):
             for o in opts:
                 o.pk = None
                 o.question = q
-                o.save()
+                o.save(force_insert=True)
 
         for q in self.questions.filter(dependency_question__isnull=False):
             q.dependency_question = question_map[q.dependency_question_id]
@@ -834,10 +853,10 @@ class Event(EventMixin, LoggedModel):
             if isinstance(rules, dict):
                 for k, v in rules.items():
                     if k == 'lookup':
-                        if v[0] == 'product':
-                            v[1] = str(item_map.get(int(v[1]), 0).pk) if int(v[1]) in item_map else "0"
-                        elif v[0] == 'variation':
-                            v[1] = str(variation_map.get(int(v[1]), 0).pk) if int(v[1]) in variation_map else "0"
+                        if rules[k][0] == 'product':
+                            rules[k][1] = str(item_map.get(int(v[1]), 0).pk) if int(v[1]) in item_map else "0"
+                        elif rules[k][0] == 'variation':
+                            rules[k][1] = str(variation_map.get(int(v[1]), 0).pk) if int(v[1]) in variation_map else "0"
                     else:
                         _walk_rules(v)
             elif isinstance(rules, list):
@@ -853,7 +872,7 @@ class Event(EventMixin, LoggedModel):
             rules = cl.rules
             _walk_rules(rules)
             cl.rules = rules
-            cl.save()
+            cl.save(force_insert=True)
             cl.log_action('pretix.object.cloned')
             for i in items:
                 cl.limit_products.add(item_map[i.pk])
@@ -862,21 +881,25 @@ class Event(EventMixin, LoggedModel):
             if other.seating_plan.organizer_id == self.organizer_id:
                 self.seating_plan = other.seating_plan
             else:
-                self.organizer.seating_plans.create(name=other.seating_plan.name, layout=other.seating_plan.layout)
+                sp = other.seating_plan
+                sp.pk = None
+                sp.organizer = self.organizer
+                sp.save(force_insert=True)
+                self.seating_plan = sp
             self.save()
 
         for m in other.seat_category_mappings.filter(subevent__isnull=True):
             m.pk = None
             m.event = self
             m.product = item_map[m.product_id]
-            m.save()
+            m.save(force_insert=True)
 
         for s in other.seats.filter(subevent__isnull=True):
             s.pk = None
             s.event = self
             if s.product_id:
                 s.product = item_map[s.product_id]
-            s.save()
+            s.save(force_insert=True)
 
         has_custom_style = other.settings.presale_css_file or other.settings.presale_widget_css_file
         skip_settings = (
@@ -1178,21 +1201,21 @@ class Event(EventMixin, LoggedModel):
             if not p.name.startswith('.') and getattr(p, 'visible', True)
         }
 
-    def set_active_plugins(self, modules, allow_restricted=False):
+    def set_active_plugins(self, modules, allow_restricted=frozenset()):
         plugins_active = self.get_plugins()
         plugins_available = self.get_available_plugins()
 
         enable = [m for m in modules if m not in plugins_active and m in plugins_available]
 
         for module in enable:
-            if getattr(plugins_available[module].app, 'restricted', False) and not allow_restricted:
+            if getattr(plugins_available[module].app, 'restricted', False) and module not in allow_restricted:
                 modules.remove(module)
             elif hasattr(plugins_available[module].app, 'installed'):
                 getattr(plugins_available[module].app, 'installed')(self)
 
         self.plugins = ",".join(modules)
 
-    def enable_plugin(self, module, allow_restricted=False):
+    def enable_plugin(self, module, allow_restricted=frozenset()):
         plugins_active = self.get_plugins()
         from pretix.presale.style import regenerate_css
 
@@ -1211,7 +1234,7 @@ class Event(EventMixin, LoggedModel):
             self.set_active_plugins(plugins_active)
 
             plugins_available = self.get_available_plugins()
-            if hasattr(plugins_available[module].app, 'uninstalled'):
+            if module in plugins_available and hasattr(plugins_available[module].app, 'uninstalled'):
                 getattr(plugins_available[module].app, 'uninstalled')(self)
 
         regenerate_css.apply_async(args=(self.pk,))
@@ -1597,3 +1620,25 @@ class SubEventMetaValue(LoggedModel):
         super().save(*args, **kwargs)
         if self.subevent:
             self.subevent.event.cache.clear()
+
+
+class EventFooterLink(models.Model):
+    """
+    A footer link assigned to an event.
+    """
+    event = models.ForeignKey('Event', on_delete=models.CASCADE, related_name='footer_links')
+    label = I18nCharField(
+        max_length=200,
+        verbose_name=_("Link text"),
+    )
+    url = models.URLField(
+        verbose_name=_("Link URL"),
+    )
+
+    def delete(self, *args, **kwargs):
+        super().delete(*args, **kwargs)
+        self.event.cache.clear()
+
+    def save(self, *args, **kwargs):
+        super().save(*args, **kwargs)
+        self.event.cache.clear()

src/pretix/base/models/fields.py

@@ -52,7 +52,10 @@ class MultiStringField(TextField):
         if isinstance(value, (list, tuple)):
             return DELIMITER + DELIMITER.join(value) + DELIMITER
         elif value is None:
-            return ""
+            if self.null:
+                return None
+            else:
+                return ""
         raise TypeError("Invalid data type passed.")
 
     def get_prep_lookup(self, lookup_type, value):  # NOQA
@@ -78,6 +81,8 @@ class MultiStringField(TextField):
             return MultiStringContains
         elif lookup_name == 'icontains':
             return MultiStringIContains
+        elif lookup_name == 'isnull':
+            return builtin_lookups.IsNull
         raise NotImplementedError(
             "Lookup '{}' doesn't work with MultiStringField".format(lookup_name),
         )