Fix migration

* API: Allow to simulate check-ins

* Add missing file

doc/api/resources/checkin.rst

@@ -71,6 +71,8 @@ Checking a ticket in
    :>json object questions: List of questions to be answered for check-in, only set on status ``"incomplete"``.
    :>json object media_policy: Reusable media policy (see documentation on items), only set on status ``"exchange"``.
    :>json object media_type: Reusable media type (see documentation on items), only set on status ``"exchange"``.
+   :>json boolean simulate: Do not actually perform the check-in, only simulate the response. The ``position`` response
+                            object will not reflect the simulated changes.
 
    **Example request**:
 

doc/api/resources/orders.rst

@@ -2038,7 +2038,7 @@ Manipulating individual positions
 
    * ``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)
+   * ``addon_to`` (optional, specified as an integer mapping to ``positionid`` - the number of the position within the order, see :ref:`_order-position-resource` - of the parent position)
 
    * ``item`` (mandatory)
 
@@ -2348,7 +2348,7 @@ otherwise, such as splitting an order or changing fees.
             "subevent": 562,
             "seat": "seat-guid-2",
             "price": "99.99",
-            "addon_to": 12374,
+            "addon_to": 1,
             "attendee_name": "Peter",
           }
         ],

src/pretix/api/serializers/checkin.py

@@ -90,6 +90,7 @@ class CheckinRPCRedeemInputSerializer(serializers.Serializer):
     answers = serializers.JSONField(required=False, allow_null=True)
     exchange_medium_type = serializers.ChoiceField(required=False, choices=MEDIA_TYPES)
     exchange_medium_identifier = serializers.CharField(required=False)
+    simulate = serializers.BooleanField(default=False, required=False)
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)

src/pretix/api/views/checkin.py

@@ -139,6 +139,7 @@ class CheckinListViewSet(viewsets.ModelViewSet):
             )
         return qs
 
+    @transaction.atomic()
     def perform_create(self, serializer):
         serializer.save(event=self.request.event)
         serializer.instance.log_action(
@@ -153,6 +154,7 @@ class CheckinListViewSet(viewsets.ModelViewSet):
         ctx['event'] = self.request.event
         return ctx
 
+    @transaction.atomic()
     def perform_update(self, serializer):
         serializer.save(event=self.request.event)
         serializer.instance.log_action(
@@ -837,6 +839,11 @@ def _redeem_process(*, checkinlists, raw_barcode, answers_data, datetime, force,
             )
 
             if exchange_medium_identifier:  # other fields are filled, see CheckinRPCRedeemInputSerializer.validate
+                if simulate:
+                    raise CheckInError(
+                        gettext('You cannot simulate a medium exchange.'),
+                        'error'
+                    )
                 with transaction.atomic():
                     # Do exchange and check-in atomically, i.e. both succeed or both fail
                     medium = perform_media_exchange(
@@ -1064,6 +1071,7 @@ class CheckinRPCRedeemView(views.APIView):
             legacy_url_support=False,
             exchange_medium_type=s.validated_data.get('exchange_medium_type'),
             exchange_medium_identifier=s.validated_data.get('exchange_medium_identifier'),
+            simulate=s.validated_data.get('simulate'),
         )
 
 

src/pretix/api/views/discount.py

@@ -32,6 +32,7 @@
 # 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.db import transaction
 from django_filters.rest_framework import DjangoFilterBackend, FilterSet
 from django_scopes import scopes_disabled
 from rest_framework import viewsets
@@ -64,6 +65,7 @@ class DiscountViewSet(ConditionalListView, viewsets.ModelViewSet):
             'limit_sales_channels',
         )
 
+    @transaction.atomic()
     def perform_create(self, serializer):
         serializer.save(event=self.request.event)
         serializer.instance.log_action(
@@ -78,6 +80,7 @@ class DiscountViewSet(ConditionalListView, viewsets.ModelViewSet):
         ctx['event'] = self.request.event
         return ctx
 
+    @transaction.atomic()
     def perform_update(self, serializer):
         serializer.save(event=self.request.event)
         serializer.instance.log_action(
@@ -87,6 +90,7 @@ class DiscountViewSet(ConditionalListView, viewsets.ModelViewSet):
             data=self.request.data
         )
 
+    @transaction.atomic()
     def perform_destroy(self, instance):
         if not instance.allow_delete():
             raise PermissionDenied('You cannot delete this discount because it already has '

src/pretix/api/views/event.py

@@ -257,6 +257,7 @@ class EventViewSet(viewsets.ModelViewSet):
                 data=self.request.data
             )
 
+    @transaction.atomic()
     def perform_create(self, serializer):
         copy_from = None
         if 'clone_from' in self.request.GET:
@@ -320,6 +321,7 @@ class EventViewSet(viewsets.ModelViewSet):
             data=self.request.data
         )
 
+    @transaction.atomic()
     def perform_destroy(self, instance):
         if not instance.allow_delete():
             raise PermissionDenied('The event can not be deleted as it already contains orders. Please set \'live\''
@@ -355,6 +357,7 @@ class CloneEventViewSet(viewsets.ModelViewSet):
         ctx['organizer'] = self.request.organizer
         return ctx
 
+    @transaction.atomic()
     def perform_create(self, serializer):
         # Weird edge case: Requires settings permission on the event (to read) but also on the organizer (two write)
         perm_holder = (self.request.auth if isinstance(self.request.auth, (Device, TeamAPIToken))
@@ -513,6 +516,7 @@ class SubEventViewSet(ConditionalListView, viewsets.ModelViewSet):
         resp['X-Page-Generated'] = date
         return resp
 
+    @transaction.atomic()
     def perform_update(self, serializer):
         original_data = self.get_serializer(instance=serializer.instance).data
         super().perform_update(serializer)
@@ -529,6 +533,7 @@ class SubEventViewSet(ConditionalListView, viewsets.ModelViewSet):
             data=self.request.data
         )
 
+    @transaction.atomic()
     def perform_create(self, serializer):
         serializer.save(event=self.request.event)
         serializer.instance.log_action(
@@ -538,6 +543,7 @@ class SubEventViewSet(ConditionalListView, viewsets.ModelViewSet):
             data=self.request.data
         )
 
+    @transaction.atomic()
     def perform_destroy(self, instance):
         if not instance.allow_delete():
             raise PermissionDenied('The sub-event can not be deleted as it has already been used in orders. Please set'
@@ -566,6 +572,7 @@ class TaxRuleViewSet(ConditionalListView, viewsets.ModelViewSet):
     def get_queryset(self):
         return self.request.event.tax_rules.all()
 
+    @transaction.atomic()
     def perform_update(self, serializer):
         super().perform_update(serializer)
         serializer.instance.log_action(
@@ -575,6 +582,7 @@ class TaxRuleViewSet(ConditionalListView, viewsets.ModelViewSet):
             data=self.request.data
         )
 
+    @transaction.atomic()
     def perform_create(self, serializer):
         serializer.save(event=self.request.event)
         serializer.instance.log_action(
@@ -584,6 +592,7 @@ class TaxRuleViewSet(ConditionalListView, viewsets.ModelViewSet):
             data=self.request.data
         )
 
+    @transaction.atomic()
     def perform_destroy(self, instance):
         if not instance.allow_delete():
             raise PermissionDenied('This tax rule can not be deleted as it is currently in use.')
@@ -757,6 +766,7 @@ class SeatViewSet(ConditionalListView, UpdateModelMixin, viewsets.ReadOnlyModelV
         }
         return ctx
 
+    @transaction.atomic()
     def perform_update(self, serializer):
         super().perform_update(serializer)
         serializer.instance.event.log_action(
@@ -766,6 +776,7 @@ class SeatViewSet(ConditionalListView, UpdateModelMixin, viewsets.ReadOnlyModelV
             data={"seats": [serializer.instance.pk]},
         )
 
+    @transaction.atomic()
     def bulk_change_blocked(self, blocked):
         s = SeatBulkBlockInputSerializer(
             data=self.request.data,

src/pretix/api/views/exporters.py

@@ -23,6 +23,7 @@ from datetime import timedelta
 
 from celery.result import AsyncResult
 from django.conf import settings
+from django.db import transaction
 from django.http import Http404
 from django.shortcuts import get_object_or_404
 from django.utils.functional import cached_property
@@ -227,6 +228,7 @@ class ScheduledEventExportViewSet(ScheduledExportersViewSet):
             qs = self.request.event.scheduled_exports
         return qs.select_related("owner")
 
+    @transaction.atomic()
     def perform_create(self, serializer):
         if not self.request.user.is_authenticated:
             raise PermissionDenied('Creation of exports requires user-specific API access.')
@@ -257,6 +259,7 @@ class ScheduledEventExportViewSet(ScheduledExportersViewSet):
         ))
         return {e.identifier: e for e in exporters}
 
+    @transaction.atomic()
     def perform_update(self, serializer):
         if not self.request.user.is_authenticated or self.request.user != serializer.instance.owner:
             # This is to prevent a possible privilege escalation where user A creates a scheduled export and
@@ -282,6 +285,7 @@ class ScheduledEventExportViewSet(ScheduledExportersViewSet):
             data=self.request.data
         )
 
+    @transaction.atomic()
     def perform_destroy(self, instance):
         self.request.event.log_action(
             'pretix.event.export.schedule.deleted',
@@ -309,6 +313,7 @@ class ScheduledOrganizerExportViewSet(ScheduledExportersViewSet):
             qs = self.request.organizer.scheduled_exports
         return qs.select_related("owner")
 
+    @transaction.atomic()
     def perform_create(self, serializer):
         if not self.request.user.is_authenticated:
             raise PermissionDenied('Creation of exports requires user-specific API access.')
@@ -339,6 +344,7 @@ class ScheduledOrganizerExportViewSet(ScheduledExportersViewSet):
         ))
         return {e.identifier: e for e in exporters}
 
+    @transaction.atomic()
     def perform_update(self, serializer):
         if not self.request.user.is_authenticated or self.request.user != serializer.instance.owner:
             # This is to prevent a possible privilege escalation where user A creates a scheduled export and
@@ -389,6 +395,7 @@ class ScheduledOrganizerExportViewSet(ScheduledExportersViewSet):
             data=self.request.data
         )
 
+    @transaction.atomic()
     def perform_destroy(self, instance):
         self.request.organizer.log_action(
             'pretix.organizer.export.schedule.deleted',

src/pretix/api/views/item.py

@@ -33,6 +33,7 @@
 # License for the specific language governing permissions and limitations under the License.
 
 import django_filters
+from django.db import transaction
 from django.db.models import Q
 from django.shortcuts import get_object_or_404
 from django.utils.functional import cached_property
@@ -109,6 +110,7 @@ class ItemViewSet(ConditionalListView, viewsets.ModelViewSet):
             'limit_sales_channels', 'variations__limit_sales_channels', 'program_times'
         ).all()
 
+    @transaction.atomic()
     def perform_create(self, serializer):
         serializer.save(event=self.request.event)
         serializer.instance.log_action(
@@ -123,6 +125,7 @@ class ItemViewSet(ConditionalListView, viewsets.ModelViewSet):
         ctx['event'] = self.request.event
         return ctx
 
+    @transaction.atomic()
     def perform_update(self, serializer):
         original_data = self.get_serializer(instance=serializer.instance).data
 
@@ -139,6 +142,7 @@ class ItemViewSet(ConditionalListView, viewsets.ModelViewSet):
             data=self.request.data
         )
 
+    @transaction.atomic()
     def perform_destroy(self, instance):
         if not instance.allow_delete():
             raise PermissionDenied('This item cannot be deleted because it has already been ordered '
@@ -183,6 +187,7 @@ class ItemVariationViewSet(viewsets.ModelViewSet):
         ctx['event'] = self.request.event
         return ctx
 
+    @transaction.atomic()
     def perform_create(self, serializer):
         item = self.item
         if not item.has_variations:
@@ -197,6 +202,7 @@ class ItemVariationViewSet(viewsets.ModelViewSet):
                              {'value': serializer.instance.value})
         )
 
+    @transaction.atomic()
     def perform_update(self, serializer):
         serializer.save(event=self.request.event)
         serializer.instance.item.log_action(
@@ -207,6 +213,7 @@ class ItemVariationViewSet(viewsets.ModelViewSet):
                              {'value': serializer.instance.value})
         )
 
+    @transaction.atomic()
     def perform_destroy(self, instance):
         if not instance.allow_delete():
             raise PermissionDenied('This variation cannot be deleted because it has already been ordered '
@@ -249,6 +256,7 @@ class ItemBundleViewSet(viewsets.ModelViewSet):
         ctx['item'] = self.item
         return ctx
 
+    @transaction.atomic()
     def perform_create(self, serializer):
         item = get_object_or_404(Item, pk=self.kwargs['item'], event=self.request.event)
         serializer.save(base_item=item)
@@ -259,6 +267,7 @@ class ItemBundleViewSet(viewsets.ModelViewSet):
             data=merge_dicts(self.request.data, {'id': serializer.instance.pk})
         )
 
+    @transaction.atomic()
     def perform_update(self, serializer):
         serializer.save(event=self.request.event)
         serializer.instance.base_item.log_action(
@@ -268,6 +277,7 @@ class ItemBundleViewSet(viewsets.ModelViewSet):
             data=merge_dicts(self.request.data, {'id': serializer.instance.pk})
         )
 
+    @transaction.atomic()
     def perform_destroy(self, instance):
         super().perform_destroy(instance)
         instance.base_item.log_action(
@@ -303,6 +313,7 @@ class ItemProgramTimeViewSet(viewsets.ModelViewSet):
         ctx['item'] = self.item
         return ctx
 
+    @transaction.atomic()
     def perform_create(self, serializer):
         item = get_object_or_404(Item, pk=self.kwargs['item'], event=self.request.event)
         serializer.save(item=item)
@@ -313,6 +324,7 @@ class ItemProgramTimeViewSet(viewsets.ModelViewSet):
             data=merge_dicts(self.request.data, {'id': serializer.instance.pk})
         )
 
+    @transaction.atomic()
     def perform_update(self, serializer):
         serializer.save(event=self.request.event)
         serializer.instance.item.log_action(
@@ -322,6 +334,7 @@ class ItemProgramTimeViewSet(viewsets.ModelViewSet):
             data=merge_dicts(self.request.data, {'id': serializer.instance.pk})
         )
 
+    @transaction.atomic()
     def perform_destroy(self, instance):
         super().perform_destroy(instance)
         instance.item.log_action(
@@ -354,6 +367,7 @@ class ItemAddOnViewSet(viewsets.ModelViewSet):
         ctx['item'] = self.item
         return ctx
 
+    @transaction.atomic()
     def perform_create(self, serializer):
         item = self.item
         category = get_object_or_404(ItemCategory, pk=self.request.data['addon_category'])
@@ -365,6 +379,7 @@ class ItemAddOnViewSet(viewsets.ModelViewSet):
             data=merge_dicts(self.request.data, {'ORDER': serializer.instance.position}, {'id': serializer.instance.pk})
         )
 
+    @transaction.atomic()
     def perform_update(self, serializer):
         serializer.save(event=self.request.event)
         serializer.instance.base_item.log_action(
@@ -374,6 +389,7 @@ class ItemAddOnViewSet(viewsets.ModelViewSet):
             data=merge_dicts(self.request.data, {'ORDER': serializer.instance.position}, {'id': serializer.instance.pk})
         )
 
+    @transaction.atomic()
     def perform_destroy(self, instance):
         super().perform_destroy(instance)
         instance.base_item.log_action(
@@ -403,6 +419,7 @@ class ItemCategoryViewSet(ConditionalListView, viewsets.ModelViewSet):
     def get_queryset(self):
         return self.request.event.categories.all()
 
+    @transaction.atomic()
     def perform_create(self, serializer):
         serializer.save(event=self.request.event)
         serializer.instance.log_action(
@@ -417,6 +434,7 @@ class ItemCategoryViewSet(ConditionalListView, viewsets.ModelViewSet):
         ctx['event'] = self.request.event
         return ctx
 
+    @transaction.atomic()
     def perform_update(self, serializer):
         serializer.save(event=self.request.event)
         serializer.instance.log_action(
@@ -426,6 +444,7 @@ class ItemCategoryViewSet(ConditionalListView, viewsets.ModelViewSet):
             data=self.request.data
         )
 
+    @transaction.atomic()
     def perform_destroy(self, instance):
         for item in instance.items.all():
             item.category = None
@@ -458,6 +477,7 @@ class QuestionViewSet(ConditionalListView, viewsets.ModelViewSet):
     def get_queryset(self):
         return self.request.event.questions.prefetch_related('options').all()
 
+    @transaction.atomic()
     def perform_create(self, serializer):
         serializer.save(event=self.request.event)
         serializer.instance.log_action(
@@ -472,6 +492,7 @@ class QuestionViewSet(ConditionalListView, viewsets.ModelViewSet):
         ctx['event'] = self.request.event
         return ctx
 
+    @transaction.atomic()
     def perform_update(self, serializer):
         serializer.save(event=self.request.event)
         serializer.instance.log_action(
@@ -481,6 +502,7 @@ class QuestionViewSet(ConditionalListView, viewsets.ModelViewSet):
             data=self.request.data
         )
 
+    @transaction.atomic()
     def perform_destroy(self, instance):
         instance.log_action(
             'pretix.event.question.deleted',
@@ -509,6 +531,7 @@ class QuestionOptionViewSet(viewsets.ModelViewSet):
         ctx['question'] = get_object_or_404(Question, pk=self.kwargs['question'], event=self.request.event)
         return ctx
 
+    @transaction.atomic()
     def perform_create(self, serializer):
         q = get_object_or_404(Question, pk=self.kwargs['question'], event=self.request.event)
         serializer.save(question=q)
@@ -519,6 +542,7 @@ class QuestionOptionViewSet(viewsets.ModelViewSet):
             data=merge_dicts(self.request.data, {'ORDER': serializer.instance.position}, {'id': serializer.instance.pk})
         )
 
+    @transaction.atomic()
     def perform_update(self, serializer):
         serializer.save(event=self.request.event)
         serializer.instance.question.log_action(
@@ -528,6 +552,7 @@ class QuestionOptionViewSet(viewsets.ModelViewSet):
             data=merge_dicts(self.request.data, {'ORDER': serializer.instance.position}, {'id': serializer.instance.pk})
         )
 
+    @transaction.atomic()
     def perform_destroy(self, instance):
         instance.question.log_action(
             'pretix.event.question.option.deleted',
@@ -586,6 +611,7 @@ class QuotaViewSet(ConditionalListView, viewsets.ModelViewSet):
         serializer = self.get_serializer(page, many=True)
         return self.get_paginated_response(serializer.data)
 
+    @transaction.atomic()
     def perform_create(self, serializer):
         serializer.save(event=self.request.event)
         serializer.instance.log_action(
@@ -608,6 +634,7 @@ class QuotaViewSet(ConditionalListView, viewsets.ModelViewSet):
         ctx['request'] = self.request
         return ctx
 
+    @transaction.atomic()
     def perform_update(self, serializer):
         original_data = self.get_serializer(instance=serializer.instance).data
 
@@ -663,6 +690,7 @@ class QuotaViewSet(ConditionalListView, viewsets.ModelViewSet):
                 )
         serializer.instance.rebuild_cache()
 
+    @transaction.atomic()
     def perform_destroy(self, instance):
         instance.log_action(
             'pretix.event.quota.deleted',

src/pretix/api/views/organizer.py

@@ -394,6 +394,7 @@ class TeamViewSet(viewsets.ModelViewSet):
         )
         return inst
 
+    @transaction.atomic()
     def perform_destroy(self, instance):
         instance.log_action('pretix.team.deleted', user=self.request.user, auth=self.request.auth)
         instance.delete()
@@ -693,6 +694,7 @@ class MembershipTypeViewSet(viewsets.ModelViewSet):
         ctx['organizer'] = self.request.organizer
         return ctx
 
+    @transaction.atomic()
     def perform_destroy(self, instance):
         if not instance.allow_delete():
             raise PermissionDenied("Can only be deleted if unused.")
@@ -833,6 +835,7 @@ class SalesChannelViewSet(viewsets.ModelViewSet):
         )
         return inst
 
+    @transaction.atomic()
     def perform_destroy(self, instance):
         if not instance.allow_delete():
             raise PermissionDenied("Can only be deleted if unused.")

src/pretix/api/views/waitinglist.py

@@ -20,6 +20,7 @@
 # <https://www.gnu.org/licenses/>.
 #
 import django_filters
+from django.db import transaction
 from django_filters.rest_framework import DjangoFilterBackend, FilterSet
 from django_scopes import scopes_disabled
 from rest_framework import viewsets
@@ -62,6 +63,7 @@ class WaitingListViewSet(viewsets.ModelViewSet):
         ctx['event'] = self.request.event
         return ctx
 
+    @transaction.atomic()
     def perform_create(self, serializer):
         serializer.save(event=self.request.event)
         serializer.instance.log_action(
@@ -70,6 +72,7 @@ class WaitingListViewSet(viewsets.ModelViewSet):
             auth=self.request.auth,
         )
 
+    @transaction.atomic()
     def perform_update(self, serializer):
         if serializer.instance.voucher:
             raise PermissionDenied('This entry can not be changed as it has already been assigned a voucher.')
@@ -80,6 +83,7 @@ class WaitingListViewSet(viewsets.ModelViewSet):
             auth=self.request.auth,
         )
 
+    @transaction.atomic()
     def perform_destroy(self, instance):
         if instance.voucher:
             raise PermissionDenied('This entry can not be deleted as it has already been assigned a voucher.')

src/pretix/api/views/webhooks.py

@@ -20,6 +20,7 @@
 # <https://www.gnu.org/licenses/>.
 #
 import django_filters
+from django.db import transaction
 from django_filters.rest_framework import DjangoFilterBackend, FilterSet
 from rest_framework import viewsets
 
@@ -48,6 +49,7 @@ class WebHookViewSet(viewsets.ModelViewSet):
         ctx['organizer'] = self.request.organizer
         return ctx
 
+    @transaction.atomic()
     def perform_create(self, serializer):
         inst = serializer.save(organizer=self.request.organizer)
         self.request.organizer.log_action(
@@ -57,6 +59,7 @@ class WebHookViewSet(viewsets.ModelViewSet):
             data=merge_dicts(self.request.data, {'id': inst.pk})
         )
 
+    @transaction.atomic()
     def perform_update(self, serializer):
         inst = serializer.save(organizer=self.request.organizer)
         self.request.organizer.log_action(
@@ -67,6 +70,7 @@ class WebHookViewSet(viewsets.ModelViewSet):
         )
         return inst
 
+    @transaction.atomic()
     def perform_destroy(self, instance):
         self.request.organizer.log_action(
             'pretix.webhook.changed',

src/pretix/base/migrations/0308_checkoutsession_invoiceaddress_checkout_session.py

@@ -0,0 +1,63 @@
+# Generated by Django 4.2.17 on 2025-01-01 20:25
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("pretixbase", "0307_devicelastseen"),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name="CheckoutSession",
+            fields=[
+                (
+                    "id",
+                    models.BigAutoField(
+                        auto_created=True, primary_key=True, serialize=False
+                    ),
+                ),
+                ("cart_id", models.CharField(max_length=255, unique=True)),
+                ("created", models.DateTimeField(auto_now_add=True)),
+                ("testmode", models.BooleanField(default=False)),
+                ("session_data", models.JSONField(default=dict)),
+                (
+                    "customer",
+                    models.ForeignKey(
+                        null=True,
+                        on_delete=django.db.models.deletion.SET_NULL,
+                        related_name="checkout_sessions",
+                        to="pretixbase.customer",
+                    ),
+                ),
+                (
+                    "event",
+                    models.ForeignKey(
+                        on_delete=django.db.models.deletion.CASCADE,
+                        related_name="checkout_sessions",
+                        to="pretixbase.event",
+                    ),
+                ),
+                (
+                    "sales_channel",
+                    models.ForeignKey(
+                        on_delete=django.db.models.deletion.CASCADE,
+                        to="pretixbase.saleschannel",
+                    ),
+                ),
+            ],
+        ),
+        migrations.AddField(
+            model_name="invoiceaddress",
+            name="checkout_session",
+            field=models.OneToOneField(
+                null=True,
+                on_delete=django.db.models.deletion.CASCADE,
+                related_name="invoice_address",
+                to="pretixbase.checkoutsession",
+            ),
+        ),
+    ]

src/pretix/base/models/orders.py

@@ -3177,6 +3177,39 @@ class Transaction(models.Model):
         return self.tax_value_includes_rounding_correction * self.count
 
 
+class CheckoutSession(models.Model):
+    """
+    A checkout session optionally bundles cart positions with additional information. This is historically
+    not required in pretix and currently only used in the Storefront API.
+    """
+    event = models.ForeignKey(
+        Event,
+        verbose_name=_("Event"),
+        related_name="checkout_sessions",
+        on_delete=models.CASCADE,
+    )
+    cart_id = models.CharField(
+        max_length=255, unique=True,
+        verbose_name=_("Cart ID (e.g. session key)"),
+    )
+    created = models.DateTimeField(
+        verbose_name=_("Date"),
+        auto_now_add=True,
+    )
+    customer = models.ForeignKey(
+        Customer,
+        related_name='checkout_sessions',
+        null=True, blank=True,
+        on_delete=models.SET_NULL,
+    )
+    sales_channel = models.ForeignKey(
+        "SalesChannel",
+        on_delete=models.CASCADE,
+    )
+    testmode = models.BooleanField(default=False)
+    session_data = models.JSONField(default=dict)
+
+
 class CartPosition(AbstractPosition):
     """
     A cart position is similar to an order line, except that it is not
@@ -3381,6 +3414,13 @@ class CartPosition(AbstractPosition):
 
 class InvoiceAddress(models.Model):
     last_modified = models.DateTimeField(auto_now=True)
+    checkout_session = models.OneToOneField(
+        CheckoutSession,
+        null=True,
+        blank=True,
+        related_name='invoice_address',
+        on_delete=models.CASCADE
+    )
     order = models.OneToOneField(Order, null=True, blank=True, related_name='invoice_address', on_delete=models.CASCADE)
     customer = models.ForeignKey(
         Customer,

src/pretix/base/services/cart.py

@@ -61,7 +61,7 @@ from pretix.base.models import (
     Seat, SeatCategoryMapping, Voucher,
 )
 from pretix.base.models.event import SubEvent
-from pretix.base.models.orders import OrderFee
+from pretix.base.models.orders import CheckoutSession, OrderFee
 from pretix.base.models.tax import TaxRule
 from pretix.base.reldate import RelativeDateWrapper
 from pretix.base.services.checkin import _save_answers
@@ -472,6 +472,16 @@ class CartManager:
                 if term_last < time_machine_now(self.real_now_dt):
                     raise CartError(error_messages['payment_ended'])
 
+    def _ensure_checkout_session(self):
+        CheckoutSession.objects.get_or_create(
+            event=self.event,
+            cart_id=self.cart_id,
+            defaults={
+                "sales_channel": self._sales_channel,
+                "testmode": self.event.testmode,
+            },
+        )
+
     def _extend_expiry_of_valid_existing_positions(self):
         # real_now_dt is initialized at CartManager instantiation, so it's slightly in the past. Add a small
         # delta to reduce risk of extending already expired CartPositions.
@@ -1559,6 +1569,7 @@ class CartManager:
 
     def commit(self):
         self._check_presale_dates()
+        self._ensure_checkout_session()
         self._check_max_cart_size()
 
         err = self._delete_out_of_timeframe()

src/pretix/base/services/checkin.py

@@ -40,7 +40,7 @@ import dateutil
 import dateutil.parser
 from dateutil.tz import datetime_exists
 from django.core.files import File
-from django.db import IntegrityError, transaction
+from django.db import IntegrityError
 from django.db.models import (
     BooleanField, Case, Count, ExpressionWrapper, F, IntegerField, Max, Min,
     OuterRef, Q, Subquery, TextField, Value, When,
@@ -59,6 +59,7 @@ from pretix.base.models import (
 )
 from pretix.base.signals import checkin_created, periodic_task
 from pretix.helpers import OF_SELF
+from pretix.helpers.database import conditional_atomic
 from pretix.helpers.jsonlogic import Logic
 from pretix.helpers.jsonlogic_boolalg import convert_to_dnf
 from pretix.helpers.jsonlogic_query import (
@@ -1043,10 +1044,10 @@ def perform_checkin(op: OrderPosition, clist: CheckinList, given_answers: dict,
         if not simulate:
             _save_answers(op, answers, given_answers)
 
-    with transaction.atomic():
+    with conditional_atomic(not simulate):
         # Lock order positions, if it is an entry. We don't need it for exits, as a race condition wouldn't be problematic
         opqs = OrderPosition.all.select_related("order", "item")
-        if type != Checkin.TYPE_EXIT:
+        if type != Checkin.TYPE_EXIT and not simulate:
             opqs = opqs.select_for_update(of=OF_SELF)
         op = opqs.get(pk=op.pk)
 

src/pretix/base/services/cleanup.py

@@ -33,6 +33,7 @@ from pretix.base.models.customers import CustomerSSOGrant
 
 from ..models import CachedFile, CartPosition, InvoiceAddress
 from ..models.auth import UserKnownLoginSource
+from ..models.orders import CheckoutSession
 from ..signals import periodic_task
 
 
@@ -43,6 +44,10 @@ def clean_cart_positions(sender, **kwargs):
         cp.delete()
     for cp in CartPosition.objects.filter(expires__lt=now() - timedelta(days=14), addon_to__isnull=True):
         cp.delete()
+    for cs in CheckoutSession.objects.filter(created__lt=now() - timedelta(days=14)).exclude(
+        Exists(CartPosition.objects.filter(cart_id=OuterRef("cart_id")))
+    ):
+        cs.delete()
     for ia in InvoiceAddress.objects.filter(order__isnull=True, customer__isnull=True, last_modified__lt=now() - timedelta(days=14)):
         ia.delete()
 

src/pretix/base/services/orders.py

@@ -73,7 +73,7 @@ from pretix.base.models import (
 )
 from pretix.base.models.event import SubEvent
 from pretix.base.models.orders import (
-    BlockedTicketSecret, InvoiceAddress, OrderFee, OrderRefund,
+    BlockedTicketSecret, CheckoutSession, InvoiceAddress, OrderFee, OrderRefund,
     generate_secret,
 )
 from pretix.base.models.organizer import SalesChannel, TeamAPIToken
@@ -1030,7 +1030,8 @@ def _apply_rounding_and_fees(positions: List[CartPosition], payment_requests: Li
 def _create_order(event: Event, *, email: str, positions: List[CartPosition], now_dt: datetime,
                   payment_requests: List[dict], sales_channel: SalesChannel, locale: str=None,
                   address: InvoiceAddress=None, meta_info: dict=None, shown_total=None,
-                  customer=None, valid_if_pending=False, api_meta: dict=None, tax_rounding_mode=None):
+                  customer=None, valid_if_pending=False, api_meta: dict=None, tax_rounding_mode=None,
+                  cart_id: str=None):
     payments = []
 
     try:
@@ -1113,6 +1114,8 @@ def _create_order(event: Event, *, email: str, positions: List[CartPosition], no
     if meta_info:
         for msg in meta_info.get('confirm_messages', []):
             order.log_action('pretix.event.order.consent', data={'msg': msg})
+    if cart_id:
+        CheckoutSession.objects.filter(event=event, cart_id=cart_id).delete()
 
     order_placed.send(event, order=order, bulk=False)
     return order, payments
@@ -1160,7 +1163,7 @@ def _order_placed_email_attendee(event: Event, order: Order, position: OrderPosi
 
 def _perform_order(event: Event, payment_requests: List[dict], position_ids: List[str],
                    email: str, locale: str, address: int, meta_info: dict=None, sales_channel: str='web',
-                   shown_total=None, customer=None, api_meta: dict=None, tax_rounding_mode=None):
+                   shown_total=None, customer=None, api_meta: dict=None, tax_rounding_mode=None, cart_id: str=None):
     for p in payment_requests:
         p['pprov'] = event.get_payment_providers(cached=True)[p['provider']]
         if not p['pprov']:
@@ -1267,6 +1270,7 @@ def _perform_order(event: Event, payment_requests: List[dict], position_ids: Lis
                 valid_if_pending=valid_if_pending,
                 api_meta=api_meta,
                 tax_rounding_mode=tax_rounding_mode,
+                cart_id=cart_id,
             )
 
             try:
@@ -3169,12 +3173,12 @@ class OrderChangeManager:
 def perform_order(self, event: Event, payments: List[dict], positions: List[str],
                   email: str=None, locale: str=None, address: int=None, meta_info: dict=None,
                   sales_channel: str='web', shown_total=None, customer=None, override_now_dt: datetime=None,
-                  api_meta: dict=None):
+                  api_meta: dict=None, cart_id: str=None):
     with language(locale), time_machine_now_assigned(override_now_dt):
         try:
             try:
                 return _perform_order(event, payments, positions, email, locale, address, meta_info,
-                                      sales_channel, shown_total, customer, api_meta)
+                                      sales_channel, shown_total, customer, api_meta, cart_id=cart_id)
             except LockTimeoutException:
                 self.retry()
         except (MaxRetriesExceededError, LockTimeoutException):

src/pretix/helpers/database.py

@@ -288,6 +288,15 @@ def get_deterministic_ordering(model, ordering):
     return ordering
 
 
+@contextlib.contextmanager
+def conditional_atomic(do_atomic, **kwargs):
+    if do_atomic:
+        with transaction.atomic(**kwargs):
+            yield
+    else:
+        yield
+
+
 class IgnoreOnSQLiteMixin:
     # Mixin to allow defining PostgreSQL-specific indexes that will just not be created
     # on SQLite. SQLite is supported for testing only anyways!

src/pretix/plugins/paypal2/payment.py

@@ -23,7 +23,7 @@ import json
 import logging
 import urllib.parse
 from collections import OrderedDict
-from datetime import timedelta
+from datetime import datetime, timedelta
 from decimal import Decimal
 
 from django import forms
@@ -645,7 +645,7 @@ class PaypalMethod(BasePaymentProvider):
     def _execute_payment(self, request: HttpRequest, payment: OrderPayment):
         payment = OrderPayment.objects.select_for_update(of=OF_SELF).get(pk=payment.pk)
         if payment.state == OrderPayment.PAYMENT_STATE_CONFIRMED:
-            logger.warning('payment is already confirmed; possible return-view/webhook race-condition')
+            # payment is already confirmed; possible return-view/webhook race-condition
             return
 
         try:
@@ -677,6 +677,8 @@ class PaypalMethod(BasePaymentProvider):
                 raise PaymentException(_('We had trouble communicating with PayPal'))
             else:
                 pp_captured_order = response.result
+                payment.info = json.dumps(pp_captured_order.dict())
+                payment.save()
 
             try:
                 ReferencedPayPalObject.objects.get_or_create(order=payment.order, payment=payment, reference=pp_captured_order.id)
@@ -830,6 +832,7 @@ class PaypalMethod(BasePaymentProvider):
                     payment.info = json.dumps(pp_captured_order.dict())
                     payment.save(update_fields=['info'])
                     payment.confirm()
+                    self.log_payment_duration(payment)
                 except Quota.QuotaExceededException as e:
                     raise PaymentException(str(e))
             # Payment has not any captures yet - so it's probably in created status
@@ -839,6 +842,20 @@ class PaypalMethod(BasePaymentProvider):
             if 'payment_paypal_oid' in request.session:
                 del request.session['payment_paypal_oid']
 
+    @staticmethod
+    def log_payment_duration(payment: OrderPayment):
+        try:
+            capture = payment.info_data["purchase_units"][0]["payments"]["captures"][0]
+            create_time: str | None = capture["create_time"]
+            update_time: str | None = capture["update_time"]
+        except (KeyError, IndexError, TypeError):
+            create_time = None
+            update_time = None
+
+        if create_time is not None and update_time is not None:
+            duration = datetime.fromisoformat(update_time) - datetime.fromisoformat(create_time)
+            logger.info('{}: {} - paypal payment processing time'.format(str(payment.global_id), str(duration)))
+
     def payment_pending_render(self, request, payment) -> str:
         retry = True
         try:

src/pretix/plugins/paypal2/views.py

@@ -357,14 +357,13 @@ def webhook(request, *args, **kwargs):
     if 'resource_type' not in event_json:
         return HttpResponse("Invalid body, no resource_type given", status=400)
 
-    if event_json['resource_type'] not in ["checkout-order", "refund", "capture"]:
-        return HttpResponse("Not interested in this resource type", status=200)
-
     # Retrieve the Charge ID of the refunded payment
-    if event_json['resource_type'] == 'refund':
+    if event_json['resource_type'] == 'checkout-order':
+        payloadid = event_json['resource']['id']
+    elif event_json['resource_type'] == 'refund' or event_json['resource_type'] == 'capture':
         payloadid = get_link(event_json['resource']['links'], 'up')['href'].split('/')[-1]
     else:
-        payloadid = event_json['resource']['id']
+        return HttpResponse("Not interested in this resource type", status=200)
 
     refs = [payloadid]
     if event_json['resource'].get('supplementary_data', {}).get('related_ids', {}).get('order_id'):
@@ -424,6 +423,8 @@ def webhook(request, *args, **kwargs):
         **event_json,
         '_order_state': sale.dict(),
     })
+    payment.info = json.dumps(sale.dict())
+    payment.save()
 
     if payment.state == OrderPayment.PAYMENT_STATE_CONFIRMED and sale['status'] in ('PARTIALLY_REFUNDED', 'REFUNDED', 'COMPLETED'):
         if event_json['resource_type'] == 'refund':
@@ -489,6 +490,7 @@ def webhook(request, *args, **kwargs):
                     payment.info = json.dumps(sale.dict())
                     payment.save(update_fields=['info'])
                     payment.confirm()
+                    prov.log_payment_duration(payment)
                 except Quota.QuotaExceededException:
                     pass
         elif sale['status'] == 'APPROVED':

src/pretix/plugins/sendmail/api.py

@@ -20,6 +20,7 @@
 # <https://www.gnu.org/licenses/>.
 #
 from django.core.exceptions import ValidationError
+from django.db import transaction
 from django_filters.rest_framework import DjangoFilterBackend, FilterSet
 from django_scopes import scopes_disabled
 from rest_framework import viewsets
@@ -118,6 +119,7 @@ class RuleViewSet(viewsets.ModelViewSet):
     def get_queryset(self):
         return Rule.objects.filter(event=self.request.event)
 
+    @transaction.atomic()
     def perform_create(self, serializer):
         super().perform_create(serializer)
         serializer.instance.log_action(
@@ -128,6 +130,7 @@ class RuleViewSet(viewsets.ModelViewSet):
 
         )
 
+    @transaction.atomic()
     def perform_update(self, serializer):
         super().perform_update(serializer)
         serializer.instance.log_action(
@@ -137,6 +140,7 @@ class RuleViewSet(viewsets.ModelViewSet):
             data=self.request.data
         )
 
+    @transaction.atomic()
     def perform_destroy(self, instance):
         instance.log_action(
             'pretix.plugins.sendmail.rule.deleted',

src/pretix/presale/checkoutflow.py

@@ -1660,6 +1660,7 @@ class ConfirmStep(CartMixin, AsyncAction, TemplateFlowStep):
             customer=self.cart_session.get('customer'),
             override_now_dt=time_machine_now(default=None),
             api_meta=api_meta,
+            cart_id=get_or_create_cart_id(request),
         )
 
     def get_success_message(self, value):

src/pretix/testutils/db.py

@@ -0,0 +1,25 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020  Raphael Michel and contributors
+# Copyright (C) 2020-today pretix 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/>.
+#
+def readonly_db(execute, sql, params, many, context):
+    if not sql.lower().startswith("select"):
+        raise Exception(f"Should not write anything to the database, but detected query: {sql}")
+    return execute(sql, params, many, context)

src/tests/api/test_checkinrpc.py

@@ -25,6 +25,7 @@ from unittest import mock
 
 import pytest
 from django.core.files.base import ContentFile
+from django.db import connection
 from django.utils.timezone import now
 from django_countries.fields import Country
 from django_scopes import scopes_disabled
@@ -36,6 +37,7 @@ from pretix.api.serializers.item import QuestionSerializer
 from pretix.base.models import (
     Checkin, InvoiceAddress, Item, Order, OrderPosition, ReusableMedium,
 )
+from pretix.testutils.db import readonly_db
 
 # Lots of this code is overlapping with test_checkin.py, and some of it is arguably redundant since it's triggering
 # the same backend code paths (for now). However, this is SUCH a critical part of pretix that we don't want to take
@@ -1739,3 +1741,41 @@ def test_exchange_create_gift_card(token_client, organizer, clist, event, order,
     with scopes_disabled():
         rm = ReusableMedium.objects.get(identifier="0412345")
         assert rm.linked_giftcard.currency == "EUR"
+
+
+@pytest.mark.django_db
+def test_simulate(token_client, organizer, clist, event, order):
+    with scopes_disabled():
+        p = order.positions.first()
+    with connection.execute_wrapper(readonly_db):
+        resp = _redeem(token_client, organizer, clist, p.secret, {"simulate": True})
+    assert resp.status_code == 201
+    assert resp.data['status'] == 'ok'
+    with scopes_disabled():
+        assert not p.checkins.exists()
+
+
+@pytest.mark.django_db
+def test_simulate_no_exchange(token_client, organizer, clist, event, order, item):
+    organizer.settings.reusable_media_type_nfc_uid = True
+    item.media_type = "nfc_uid"
+    item.media_policy = Item.MEDIA_POLICY_NEW
+    item.save()
+    with scopes_disabled():
+        rm = ReusableMedium.objects.create(
+            type="nfc_uid",
+            identifier="12345678",
+            organizer=organizer,
+        )
+    with connection.execute_wrapper(readonly_db):
+        resp = _redeem(token_client, organizer, clist, "z3fsn8jyufm5kpk768q69gkbyr5f4h6w", {
+            "source_type": "barcode",
+            "exchange_medium_type": "nfc_uid",
+            "exchange_medium_identifier": "12345678",
+            "simulate": True,
+        })
+    assert resp.status_code == 400
+    assert resp.data['status'] == 'error'
+    assert resp.data['reason'] == 'error'
+    with scopes_disabled():
+        assert not rm.linked_orderpositions.exists()

src/tests/control/test_views.py

@@ -224,3 +224,28 @@ def test_one_view(logged_in_client, url, expected, event, item, item_category, o
         )
     response = logged_in_client.get(url)
     assert response.status_code == expected
+
+    # Do not reintroduce any CSP nonces into control responses, as discussed in PR #6387
+    if response['Content-Type'] != 'application/json':
+        assert 'script-src' in response['Content-Security-Policy']
+        assert 'nonce-' not in response['Content-Security-Policy']
+
+
+@pytest.mark.parametrize('url', [
+    '/control/login',
+    '/',
+    '/{orga}/{event}/',
+])
+@pytest.mark.django_db
+def test_csp_header_unauthenticated(client, url, event):
+    # Do not reintroduce any CSP nonces into most presale responses, as discussed in PR #6387
+    with scope(organizer=event.organizer):
+        url = url.format(
+            event=event.slug, orga=event.organizer.slug,
+        )
+        event.live = True
+        event.save()
+    response = client.get(url)
+    assert response.status_code == 200
+    assert 'script-src' in response['Content-Security-Policy']
+    assert 'nonce-' not in response['Content-Security-Policy']

src/tests/plugins/paypal2/test_webhook.py

@@ -22,6 +22,7 @@
 import json
 from datetime import timedelta
 from decimal import Decimal
+from unittest.mock import MagicMock
 
 import pytest
 from django.utils.timezone import now
@@ -409,7 +410,8 @@ def test_webhook_mark_paid(env, client, monkeypatch):
         order.payments.update(state=OrderPayment.PAYMENT_STATE_PENDING)
 
     pp_order = Result(get_test_order())
-    monkeypatch.setattr("paypalcheckoutsdk.orders.OrdersGetRequest", lambda *args: pp_order)
+    mock_orders_get_request = MagicMock(return_value=pp_order)
+    monkeypatch.setattr("paypalcheckoutsdk.orders.OrdersGetRequest", mock_orders_get_request)
     monkeypatch.setattr("pretix.plugins.paypal2.payment.PaypalMethod.init_api", init_api)
     with scopes_disabled():
         ReferencedPayPalObject.objects.create(order=order, payment=order.payments.first(),
@@ -497,7 +499,7 @@ def test_webhook_mark_paid(env, client, monkeypatch):
             "resource_version": "2.0"
         }
     ), content_type='application_json')
-
+    mock_orders_get_request.assert_called_once_with('806440346Y391300T')
     order.refresh_from_db()
     assert order.status == Order.STATUS_PAID