Fix special case if addon product is now set to require a voucher (vouchers for addons are not supported)

Order has product with addon 1
Addon 1 is hidden if Addon 2 is available
When order is changed, Addon 1 should not be removable

src/pretix/base/models/items.py

@@ -885,26 +885,6 @@ class Item(LoggedModel):
             return False
         return True
 
-    def unavailability_reason(self, now_dt: datetime=None, has_voucher=False, subevent=None) -> Optional[str]:
-        now_dt = now_dt or time_machine_now()
-        subevent_item = subevent and subevent.item_overrides.get(self.pk)
-        if not self.active:
-            return 'active'
-        elif self.available_from and self.available_from > now_dt:
-            return 'available_from'
-        elif self.available_until and self.available_until < now_dt:
-            return 'available_until'
-        elif (self.require_voucher or self.hide_without_voucher) and not has_voucher:
-            return 'require_voucher'
-        elif subevent_item and subevent_item.available_from and subevent_item.available_from > now_dt:
-            return 'available_from'
-        elif subevent_item and subevent_item.available_until and subevent_item.available_until < now_dt:
-            return 'available_until'
-        elif self.hidden_if_item_available and self._dependency_available:
-            return 'hidden_if_item_available'
-        else:
-            return None
-
     def _get_quotas(self, ignored_quotas=None, subevent=None):
         check_quotas = set(getattr(
             self, '_subevent_quotas',  # Utilize cache in product list
@@ -1413,22 +1393,6 @@ class ItemVariation(models.Model):
             return False
         return True
 
-    def unavailability_reason(self, now_dt: datetime=None, has_voucher=False, subevent=None) -> Optional[str]:
-        now_dt = now_dt or time_machine_now()
-        subevent_var = subevent and subevent.var_overrides.get(self.pk)
-        if not self.active:
-            return 'active'
-        elif self.available_from and self.available_from > now_dt:
-            return 'available_from'
-        elif self.available_until and self.available_until < now_dt:
-            return 'available_until'
-        elif subevent_var and subevent_var.available_from and subevent_var.available_from > now_dt:
-            return 'available_from'
-        elif subevent_var and subevent_var.available_until and subevent_var.available_until < now_dt:
-            return 'available_until'
-        else:
-            return None
-
     @property
     def meta_data(self):
         data = self.item.meta_data

src/pretix/base/services/cross_selling.py

@@ -29,7 +29,7 @@ from typing import List
 from django.utils.functional import cached_property
 
 from pretix.base.models import CartPosition, ItemCategory, SalesChannel
-from pretix.presale.views.event import get_grouped_items
+from pretix.presale.productlist import prepare_item_list_for_shop
 
 
 class DummyCategory:
@@ -162,7 +162,7 @@ class CrossSellingService:
         ]
 
     def _prepare_items(self, subevent, items_qs, discount_info):
-        items, _btn = get_grouped_items(
+        items, _btn = prepare_item_list_for_shop(
             self.event,
             subevent=subevent,
             voucher=None,

src/pretix/base/services/orders.py

@@ -110,6 +110,7 @@ from pretix.celery_app import app
 from pretix.helpers import OF_SELF
 from pretix.helpers.models import modelcopy
 from pretix.helpers.periodic import minimum_interval
+from pretix.presale.productlist import prepare_item_list_for_shop
 from pretix.testutils.middleware import debugflags_var
 
 
@@ -1943,13 +1944,18 @@ class OrderChangeManager:
 
         :param addons: A list of dictionaries with the keys ``"addon_to"``, ``"item"``, ``"variation"`` (all ID values),
                        ``"count"``, and ``"price"``.
-        :param limit_main_positions: By default, the method works on all methods of the order. If you set this to a
+        :param limit_main_positions: By default, the method works on all positions of the order. If you set this to a
                                      queryset or a list of positions, all other positions and their add-ons will be kept
                                      untouched.
         """
         if self._operations:
             raise ValueError("Setting addons should be the first/only operation")
 
+        def _allowed_on_order_sales_channel(item_or_var, order):
+            return item_or_var.all_sales_channels or (
+                order.sales_channel.identifier in (s.identifier for s in item_or_var.limit_sales_channels.all())
+            )
+
         # Prepare containers for min/max check of products
         item_counts = Counter()
         for p in self.order.positions.all():
@@ -2043,13 +2049,11 @@ class OrderChangeManager:
             if not item.is_available() or (variation and not variation.is_available()):
                 raise OrderError(error_messages['unavailable'])
 
-            if not item.all_sales_channels:
-                if self.order.sales_channel.identifier not in (s.identifier for s in item.limit_sales_channels.all()):
-                    raise OrderError(error_messages['unavailable'])
+            if not _allowed_on_order_sales_channel(item, self.order):
+                raise OrderError(error_messages['unavailable'])
 
-            if variation and not variation.all_sales_channels:
-                if self.order.sales_channel.identifier not in (s.identifier for s in variation.limit_sales_channels.all()):
-                    raise OrderError(error_messages['unavailable'])
+            if variation and not _allowed_on_order_sales_channel(variation, self.order):
+                raise OrderError(error_messages['unavailable'])
 
             if subevent and item.pk in subevent.item_overrides and not subevent.item_overrides[item.pk].is_available():
                 raise OrderError(error_messages['not_for_sale'])
@@ -2097,6 +2101,36 @@ class OrderChangeManager:
                     )
                     item_counts[item] += 1
 
+        def _addon_is_available(a):
+            # If an item is no longer available due to time, it should usually also be no longer
+            # user-removable, because e.g. the stock has already been ordered.
+            # We always set voucher=None because that's what's done when generating the form in
+            # OrderChangeMixin (vouchers for addons are not supported).
+            # This also prevents accidental removal through the UI because a hidden product will no longer
+            # be part of the input.
+            if not _allowed_on_order_sales_channel(a.item, self.order) or (
+                a.variation and not _allowed_on_order_sales_channel(a.variation, self.order)
+            ):
+                return False
+
+            items, _ = prepare_item_list_for_shop(
+                self.order.event,
+                channel=self.order.sales_channel,
+                subevent=a.subevent,
+                voucher=None,
+                base_qs=Item.objects.filter(pk=a.item.pk),
+                allow_addons=True
+            )
+            if (not items) or items[0].current_unavailability_reason:
+                return False
+
+            if a.variation:
+                variations = [var for var in items[0].available_variations if var.pk == a.variation.pk]
+                if (not variations) or variations[0].current_unavailability_reason:
+                    return False
+
+            return True
+
         # Detect removed add-ons and create RemoveOperations
         for cp, al in list(current_addons.items()):
             for k, v in al.items():
@@ -2106,22 +2140,7 @@ class OrderChangeManager:
                     for a in current_addons[cp][k][:current_num - input_num]:
                         if a.canceled:
                             continue
-                        is_unavailable = (
-                            # If an item is no longer available due to time, it should usually also be no longer
-                            # user-removable, because e.g. the stock has already been ordered.
-                            # We always pass has_voucher=True because if a product now requires a voucher, it usually does
-                            # not mean it should be unremovable for others.
-                            # This also prevents accidental removal through the UI because a hidden product will no longer
-                            # be part of the input.
-                            (a.variation and a.variation.unavailability_reason(has_voucher=True, subevent=a.subevent))
-                            or (a.variation and not a.variation.all_sales_channels and not a.variation.limit_sales_channels.contains(self.order.sales_channel))
-                            or a.item.unavailability_reason(has_voucher=True, subevent=a.subevent)
-                            or (
-                                not a.item.all_sales_channels and
-                                not a.item.limit_sales_channels.contains(self.order.sales_channel)
-                            )
-                        )
-                        if is_unavailable:
+                        if not _addon_is_available(a):
                             # "Re-select" add-on
                             selected_addons[cp.id, a.item.category_id][a.item_id, a.variation_id] += 1
                             continue

src/pretix/presale/checkoutflow.py

@@ -87,6 +87,7 @@ from pretix.presale.forms.checkout import (
     ContactForm, InvoiceAddressForm, InvoiceNameForm, MembershipForm,
 )
 from pretix.presale.forms.customer import AuthenticationForm, RegistrationForm
+from pretix.presale.productlist import prepare_item_list_for_shop
 from pretix.presale.signals import (
     checkout_all_optional, checkout_confirm_messages, checkout_flow_steps,
     contact_form_fields, contact_form_fields_overrides,
@@ -99,7 +100,6 @@ from pretix.presale.views.cart import (
     _items_from_post_data, cart_session, create_empty_cart_id,
     get_or_create_cart_id,
 )
-from pretix.presale.views.event import get_grouped_items
 from pretix.presale.views.questions import QuestionsViewMixin
 
 
@@ -603,7 +603,7 @@ class AddOnsStep(CartMixin, AsyncAction, TemplateFlowStep):
 
                 if ckey not in item_cache:
                     # Get all items to possibly show
-                    items, _btn = get_grouped_items(
+                    items, _btn = prepare_item_list_for_shop(
                         self.request.event,
                         subevent=cartpos.subevent,
                         voucher=None,

src/pretix/presale/productlist.py

@@ -0,0 +1,460 @@
+#
+# 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/>.
+#
+import sys
+from datetime import datetime
+from typing import Optional
+
+from django.conf import settings
+from django.db.models import (
+    Count, Exists, IntegerField, OuterRef, Prefetch, Q, Value,
+)
+from django.db.models.lookups import Exact
+
+from pretix.base.models import (
+    ItemVariation, Quota, SalesChannel, SeatCategoryMapping,
+)
+from pretix.base.models.items import (
+    Item, ItemAddOn, ItemBundle, SubEventItem, SubEventItemVariation,
+)
+from pretix.base.services.quotas import QuotaAvailability
+from pretix.base.timemachine import time_machine_now
+from pretix.presale.signals import item_description
+
+
+def item_group_by_category(items):
+    return sorted(
+        [
+            # a group is a tuple of a category and a list of items
+            (cat, [i for i in items if i.category == cat])
+            for cat in set([i.category for i in items])
+            # insert categories into a set for uniqueness
+            # a set is unsorted, so sort again by category
+        ],
+        key=lambda group: (group[0].position, group[0].id) if (
+            group[0] is not None and group[0].id is not None) else (0, 0)
+    )
+
+
+def prepare_item_list_for_shop(event, *, channel: SalesChannel, subevent=None, voucher=None, require_seat=0, base_qs=None,
+                               allow_addons=False, allow_cross_sell=False,
+                               quota_cache=None, filter_items=None, filter_categories=None, memberships=None,
+                               ignore_hide_sold_out_for_item_ids=None):
+    base_qs_set = base_qs is not None
+    base_qs = base_qs if base_qs is not None else event.items
+
+    requires_seat = Exists(
+        SeatCategoryMapping.objects.filter(
+            product_id=OuterRef('pk'),
+            subevent=subevent
+        )
+    )
+    if not event.settings.seating_choice:
+        requires_seat = Value(0, output_field=IntegerField())
+
+    variation_q = (
+        Q(Q(available_from__isnull=True) | Q(available_from__lte=time_machine_now()) | Q(available_from_mode='info')) &
+        Q(Q(available_until__isnull=True) | Q(available_until__gte=time_machine_now()) | Q(available_until_mode='info'))
+    )
+    if not voucher or not voucher.show_hidden_items:
+        variation_q &= Q(hide_without_voucher=False)
+
+    if memberships is not None:
+        prefetch_membership_types = ['require_membership_types']
+    else:
+        prefetch_membership_types = []
+
+    prefetch_var = Prefetch(
+        'variations',
+        to_attr='available_variations',
+        queryset=ItemVariation.objects.using(settings.DATABASE_REPLICA).annotate(
+            subevent_disabled=Exists(
+                SubEventItemVariation.objects.filter(
+                    Q(disabled=True)
+                    | (Exact(OuterRef('available_from_mode'), 'hide') & Q(available_from__gt=time_machine_now()))
+                    | (Exact(OuterRef('available_until_mode'), 'hide') & Q(available_until__lt=time_machine_now())),
+                    variation_id=OuterRef('pk'),
+                    subevent=subevent,
+                )
+            ),
+        ).filter(
+            variation_q,
+            Q(all_sales_channels=True) | Q(limit_sales_channels=channel),
+            Exists(Quota.variations.through.objects.filter(quota__subevent_id=subevent, itemvariation_id=OuterRef("pk"))),
+            active=True,
+            subevent_disabled=False
+        ).prefetch_related(
+            *prefetch_membership_types,
+            Prefetch('quotas',
+                     to_attr='_subevent_quotas',
+                     queryset=event.quotas.using(settings.DATABASE_REPLICA).filter(
+                         subevent=subevent).select_related("subevent"))
+        ).distinct()
+    )
+    prefetch_quotas = Prefetch(
+        'quotas',
+        to_attr='_subevent_quotas',
+        queryset=event.quotas.using(settings.DATABASE_REPLICA).filter(subevent=subevent).select_related("subevent")
+    )
+    prefetch_bundles = Prefetch(
+        'bundles',
+        queryset=ItemBundle.objects.using(settings.DATABASE_REPLICA).prefetch_related(
+            Prefetch('bundled_item',
+                     queryset=event.items.using(settings.DATABASE_REPLICA).select_related(
+                         'tax_rule').prefetch_related(
+                         Prefetch('quotas',
+                                  to_attr='_subevent_quotas',
+                                  queryset=event.quotas.using(settings.DATABASE_REPLICA).filter(
+                                      subevent=subevent)),
+                     )),
+            Prefetch('bundled_variation',
+                     queryset=ItemVariation.objects.using(
+                         settings.DATABASE_REPLICA
+                     ).select_related('item', 'item__tax_rule').filter(item__event=event).prefetch_related(
+                         Prefetch('quotas',
+                                  to_attr='_subevent_quotas',
+                                  queryset=event.quotas.using(settings.DATABASE_REPLICA).filter(
+                                      subevent=subevent)),
+                     )),
+        )
+    )
+
+    items = base_qs.using(settings.DATABASE_REPLICA).filter_available(
+        channel=channel.identifier, voucher=voucher, allow_addons=allow_addons, allow_cross_sell=allow_cross_sell
+    ).select_related(
+        'category', 'tax_rule',  # for re-grouping
+        'hidden_if_available',
+    ).prefetch_related(
+        *prefetch_membership_types,
+        Prefetch(
+            'hidden_if_item_available',
+            queryset=event.items.annotate(
+                has_variations=Count('variations'),
+            ).prefetch_related(
+                prefetch_var,
+                prefetch_quotas,
+                prefetch_bundles,
+            )
+        ),
+        prefetch_quotas,
+        prefetch_var,
+        prefetch_bundles,
+    ).annotate(
+        has_variations=Count('variations'),
+        subevent_disabled=Exists(
+            SubEventItem.objects.filter(
+                Q(disabled=True)
+                | (Exact(OuterRef('available_from_mode'), 'hide') & Q(available_from__gt=time_machine_now()))
+                | (Exact(OuterRef('available_until_mode'), 'hide') & Q(available_until__lt=time_machine_now())),
+                item_id=OuterRef('pk'),
+                subevent=subevent,
+            )
+        ),
+        mandatory_priced_addons=Exists(
+            ItemAddOn.objects.filter(
+                base_item_id=OuterRef('pk'),
+                min_count__gte=1,
+                price_included=False
+            )
+        ),
+        requires_seat=requires_seat,
+    ).filter(
+        Exists(Quota.items.through.objects.filter(quota__subevent_id=subevent, item_id=OuterRef("pk"))),
+        subevent_disabled=False,
+    ).order_by('category__position', 'category_id', 'position', 'name')
+    if require_seat:
+        items = items.filter(requires_seat__gt=0)
+    elif require_seat is not None:
+        items = items.filter(requires_seat=0)
+
+    if filter_items:
+        items = items.filter(pk__in=[a for a in filter_items if a.isdigit()])
+    if filter_categories:
+        items = items.filter(category_id__in=[a for a in filter_categories if a.isdigit()])
+
+    display_add_to_cart = False
+    quota_cache_key = f'item_quota_cache:{subevent.id if subevent else 0}:{channel.identifier}:{bool(require_seat)}'
+    quota_cache = quota_cache or event.cache.get(quota_cache_key) or {}
+    quota_cache_existed = bool(quota_cache)
+
+    if subevent:
+        item_price_override = subevent.item_price_overrides
+        var_price_override = subevent.var_price_overrides
+    else:
+        item_price_override = {}
+        var_price_override = {}
+
+    restrict_vars = set()
+    if voucher and voucher.quota_id:
+        # If a voucher is set to a specific quota, we need to filter out on that level
+        restrict_vars = set(voucher.quota.variations.all())
+
+    quotas_to_compute = []
+    for item in items:
+        assert item.event_id == event.pk
+        item.event = event  # save a database query if this is looked up
+        if item.has_variations:
+            for v in item.available_variations:
+                for q in v._subevent_quotas:
+                    if q.pk not in quota_cache:
+                        quotas_to_compute.append(q)
+        else:
+            for q in item._subevent_quotas:
+                if q.pk not in quota_cache:
+                    quotas_to_compute.append(q)
+
+    if quotas_to_compute:
+        qa = QuotaAvailability()
+        qa.queue(*quotas_to_compute)
+        qa.compute()
+        quota_cache.update({q.pk: r for q, r in qa.results.items()})
+
+    for item in items:
+        if voucher and voucher.item_id and voucher.variation_id:
+            # Restrict variations if the voucher only allows one
+            item.available_variations = [v for v in item.available_variations
+                                         if v.pk == voucher.variation_id]
+
+        if channel.type_instance.unlimited_items_per_order:
+            max_per_order = sys.maxsize
+        else:
+            max_per_order = item.max_per_order or int(event.settings.max_items_per_order)
+        if voucher:
+            max_per_order = min(max_per_order, voucher.max_usages - voucher.redeemed)
+
+        if item.hidden_if_available:
+            q = item.hidden_if_available.availability(_cache=quota_cache)
+            if q[0] == Quota.AVAILABILITY_OK:
+                item._remove = True
+                continue
+
+        if item.hidden_if_item_available:
+            if item.hidden_if_item_available.has_variations:
+                item._dependency_available = any(
+                    var.check_quotas(subevent=subevent, _cache=quota_cache, include_bundled=True)[0] == Quota.AVAILABILITY_OK
+                    for var in item.hidden_if_item_available.available_variations
+                )
+            else:
+                q = item.hidden_if_item_available.check_quotas(subevent=subevent, _cache=quota_cache, include_bundled=True)
+                time_available = item.hidden_if_item_available.is_available()
+                item._dependency_available = (q[0] == Quota.AVAILABILITY_OK) and time_available
+            if item._dependency_available and item.hidden_if_item_available_mode == Item.UNAVAIL_MODE_HIDDEN:
+                item._remove = True
+                continue
+
+        if item.require_membership and item.require_membership_hidden:
+            if not memberships or not any([m.membership_type in item.require_membership_types.all() for m in memberships]):
+                item._remove = True
+                continue
+
+        item.current_unavailability_reason = _get_item_unavailability_reason(item, has_voucher=voucher, subevent=subevent)
+
+        item.description = str(item.description)
+        for recv, resp in item_description.send(sender=event, item=item, variation=None, subevent=subevent):
+            if resp:
+                item.description += ("<br/>" if item.description else "") + resp
+
+        if not item.has_variations:
+            item._remove = False
+            if not bool(item._subevent_quotas):
+                item._remove = True
+                continue
+
+            if voucher and (voucher.allow_ignore_quota or voucher.block_quota):
+                item.cached_availability = (
+                    Quota.AVAILABILITY_OK, voucher.max_usages - voucher.redeemed
+                )
+            else:
+                item.cached_availability = list(
+                    item.check_quotas(subevent=subevent, _cache=quota_cache, include_bundled=True)
+                )
+
+            if not (
+                    ignore_hide_sold_out_for_item_ids and item.pk in ignore_hide_sold_out_for_item_ids
+            ) and event.settings.hide_sold_out and item.cached_availability[0] < Quota.AVAILABILITY_RESERVED:
+                item._remove = True
+                continue
+
+            item.order_max = min(
+                item.cached_availability[1]
+                if item.cached_availability[1] is not None else sys.maxsize,
+                max_per_order
+            )
+
+            original_price = item_price_override.get(item.pk, item.default_price)
+            voucher_reduced = False
+            if voucher:
+                price = voucher.calculate_price(original_price)
+                voucher_reduced = price < original_price
+                include_bundled = not voucher.all_bundles_included
+            else:
+                price = original_price
+                include_bundled = True
+
+            item.display_price = item.tax(price, currency=event.currency, include_bundled=include_bundled)
+            if item.free_price and item.free_price_suggestion is not None and not voucher_reduced:
+                item.suggested_price = item.tax(max(price, item.free_price_suggestion), currency=event.currency, include_bundled=include_bundled)
+            else:
+                item.suggested_price = item.display_price
+
+            if price != original_price:
+                item.original_price = item.tax(original_price, currency=event.currency, include_bundled=True)
+            else:
+                item.original_price = (
+                    item.tax(item.original_price, currency=event.currency, include_bundled=True,
+                             base_price_is='net' if event.settings.display_net_prices else 'gross')  # backwards-compat
+                    if item.original_price else None
+                )
+            if not display_add_to_cart:
+                display_add_to_cart = not item.requires_seat and item.order_max > 0
+        else:
+            for var in item.available_variations:
+                if var.require_membership and var.require_membership_hidden:
+                    if not memberships or not any([m.membership_type in var.require_membership_types.all() for m in memberships]):
+                        var._remove = True
+                        continue
+
+                var.description = str(var.description)
+                for recv, resp in item_description.send(sender=event, item=item, variation=var, subevent=subevent):
+                    if resp:
+                        var.description += ("<br/>" if var.description else "") + resp
+
+                if voucher and (voucher.allow_ignore_quota or voucher.block_quota):
+                    var.cached_availability = (
+                        Quota.AVAILABILITY_OK, voucher.max_usages - voucher.redeemed
+                    )
+                else:
+                    var.cached_availability = list(
+                        var.check_quotas(subevent=subevent, _cache=quota_cache, include_bundled=True)
+                    )
+
+                var.order_max = min(
+                    var.cached_availability[1]
+                    if var.cached_availability[1] is not None else sys.maxsize,
+                    max_per_order
+                )
+
+                original_price = var_price_override.get(var.pk, var.price)
+                voucher_reduced = False
+                if voucher:
+                    price = voucher.calculate_price(original_price)
+                    voucher_reduced = price < original_price
+                    include_bundled = not voucher.all_bundles_included
+                else:
+                    price = original_price
+                    include_bundled = True
+
+                var.display_price = var.tax(price, currency=event.currency, include_bundled=include_bundled)
+
+                if item.free_price and var.free_price_suggestion is not None and not voucher_reduced:
+                    var.suggested_price = item.tax(max(price, var.free_price_suggestion), currency=event.currency,
+                                                   include_bundled=include_bundled)
+                elif item.free_price and item.free_price_suggestion is not None and not voucher_reduced:
+                    var.suggested_price = item.tax(max(price, item.free_price_suggestion), currency=event.currency,
+                                                   include_bundled=include_bundled)
+                else:
+                    var.suggested_price = var.display_price
+
+                if price != original_price:
+                    var.original_price = var.tax(original_price, currency=event.currency, include_bundled=True)
+                else:
+                    var.original_price = (
+                        var.tax(var.original_price or item.original_price, currency=event.currency,
+                                include_bundled=True,
+                                base_price_is='net' if event.settings.display_net_prices else 'gross')  # backwards-compat
+                    ) if var.original_price or item.original_price else None
+
+                var.current_unavailability_reason = _get_variant_unavailability_reason(var, has_voucher=voucher, subevent=subevent)
+
+            item.original_price = (
+                item.tax(item.original_price, currency=event.currency, include_bundled=True,
+                         base_price_is='net' if event.settings.display_net_prices else 'gross')  # backwards-compat
+                if item.original_price else None
+            )
+
+            item.available_variations = [
+                v for v in item.available_variations if v._subevent_quotas and (
+                    not voucher or not voucher.quota_id or v in restrict_vars
+                ) and not getattr(v, '_remove', False)
+            ]
+
+            if not (ignore_hide_sold_out_for_item_ids and item.pk in ignore_hide_sold_out_for_item_ids) and event.settings.hide_sold_out:
+                item.available_variations = [v for v in item.available_variations
+                                             if v.cached_availability[0] >= Quota.AVAILABILITY_RESERVED]
+
+            if voucher and voucher.variation_id:
+                item.available_variations = [v for v in item.available_variations
+                                             if v.pk == voucher.variation_id]
+
+            if len(item.available_variations) > 0:
+                item.min_price = min([v.display_price.net if event.settings.display_net_prices else
+                                      v.display_price.gross for v in item.available_variations])
+                item.max_price = max([v.display_price.net if event.settings.display_net_prices else
+                                      v.display_price.gross for v in item.available_variations])
+                item.best_variation_availability = max([v.cached_availability[0] for v in item.available_variations])
+
+            item._remove = not bool(item.available_variations)
+            if not item._remove and not display_add_to_cart:
+                display_add_to_cart = not item.requires_seat and any(v.order_max > 0 for v in item.available_variations)
+
+    if not quota_cache_existed and not voucher and not allow_addons and not base_qs_set and not filter_items and not filter_categories:
+        event.cache.set(quota_cache_key, quota_cache, 5)
+    items = [item for item in items
+             if (len(item.available_variations) > 0 or not item.has_variations) and not item._remove]
+    return items, display_add_to_cart
+
+
+def _get_item_unavailability_reason(item, now_dt: Optional[datetime]=None, has_voucher=False, subevent=None) -> Optional[str]:
+    now_dt = now_dt or time_machine_now()
+    subevent_item = subevent and subevent.item_overrides.get(item.pk)
+    if not item.active:
+        return 'active'
+    elif item.available_from and item.available_from > now_dt:
+        return 'available_from'
+    elif item.available_until and item.available_until < now_dt:
+        return 'available_until'
+    elif (item.require_voucher or item.hide_without_voucher) and not has_voucher:
+        return 'require_voucher'
+    elif subevent_item and subevent_item.available_from and subevent_item.available_from > now_dt:
+        return 'available_from'
+    elif subevent_item and subevent_item.available_until and subevent_item.available_until < now_dt:
+        return 'available_until'
+    elif item.hidden_if_item_available and item._dependency_available:
+        return 'hidden_if_item_available'
+    else:
+        return None
+
+
+def _get_variant_unavailability_reason(variant, now_dt: Optional[datetime]=None, has_voucher=False, subevent=None) -> Optional[str]:
+    now_dt = now_dt or time_machine_now()
+    subevent_var = subevent and subevent.var_overrides.get(variant.pk)
+    if not variant.active:
+        return 'active'
+    elif variant.available_from and variant.available_from > now_dt:
+        return 'available_from'
+    elif variant.available_until and variant.available_until < now_dt:
+        return 'available_until'
+    elif subevent_var and subevent_var.available_from and subevent_var.available_from > now_dt:
+        return 'available_from'
+    elif subevent_var and subevent_var.available_until and subevent_var.available_until < now_dt:
+        return 'available_until'
+    else:
+        return None

src/pretix/presale/views/cart.py

@@ -68,13 +68,13 @@ from pretix.base.timemachine import time_machine_now
 from pretix.base.views.tasks import AsyncAction
 from pretix.helpers.http import redirect_to_url
 from pretix.multidomain.urlreverse import eventreverse
+from pretix.presale.productlist import (
+    item_group_by_category, prepare_item_list_for_shop,
+)
 from pretix.presale.views import (
     CartMixin, EventViewMixin, allow_cors_if_namespaced,
     allow_frame_if_namespaced, get_cart, iframe_entry_view_wrapper,
 )
-from pretix.presale.views.event import (
-    get_grouped_items, item_group_by_category,
-)
 from pretix.presale.views.robots import NoSearchIndexViewMixin
 
 try:
@@ -669,7 +669,7 @@ class RedeemView(NoSearchIndexViewMixin, EventViewMixin, CartMixin, TemplateView
         context['max_times'] = self.voucher.max_usages - self.voucher.redeemed
 
         # Fetch all items
-        items, display_add_to_cart = get_grouped_items(
+        items, display_add_to_cart = prepare_item_list_for_shop(
             self.request.event,
             subevent=self.subevent,
             voucher=self.voucher,

src/pretix/presale/views/event.py

@@ -34,7 +34,6 @@
 
 import calendar
 import hashlib
-import sys
 from collections import defaultdict
 from datetime import date, datetime, timedelta
 from decimal import Decimal
@@ -47,10 +46,7 @@ from django import forms
 from django.conf import settings
 from django.contrib import messages
 from django.core.exceptions import PermissionDenied
-from django.db.models import (
-    Count, Exists, IntegerField, OuterRef, Prefetch, Q, Value,
-)
-from django.db.models.lookups import Exact
+from django.db.models import Count
 from django.http import Http404, HttpResponse
 from django.shortcuts import get_object_or_404, redirect, render
 from django.utils.decorators import method_decorator
@@ -65,15 +61,9 @@ from django.views.generic import TemplateView
 
 from pretix.base.auth import has_event_access_permission
 from pretix.base.forms.widgets import SplitDateTimePickerWidget
-from pretix.base.models import (
-    ItemVariation, Quota, SalesChannel, SeatCategoryMapping, Voucher,
-)
+from pretix.base.models import Quota, Voucher
 from pretix.base.models.event import Event, SubEvent
-from pretix.base.models.items import (
-    Item, ItemAddOn, ItemBundle, SubEventItem, SubEventItemVariation,
-)
 from pretix.base.services.placeholders import PlaceholderContext
-from pretix.base.services.quotas import QuotaAvailability
 from pretix.base.timemachine import time_machine_now
 from pretix.helpers.compat import date_fromisocalendar
 from pretix.helpers.formats.en.formats import (
@@ -82,7 +72,10 @@ from pretix.helpers.formats.en.formats import (
 from pretix.helpers.http import redirect_to_url
 from pretix.multidomain.urlreverse import eventreverse
 from pretix.presale.ical import get_public_ical
-from pretix.presale.signals import item_description, seatingframe_html_head
+from pretix.presale.productlist import (
+    item_group_by_category, prepare_item_list_for_shop,
+)
+from pretix.presale.signals import seatingframe_html_head
 from pretix.presale.views.organizer import (
     EventListMixin, add_subevents_for_days, days_for_template,
     filter_qs_by_attr, filter_subevents_with_plugins, has_before_after,
@@ -94,391 +87,12 @@ from . import (
     iframe_entry_view_wrapper,
 )
 
+from pretix.presale.productlist import prepare_item_list_for_shop as get_grouped_items  # noqa
+
+
 SessionStore = import_module(settings.SESSION_ENGINE).SessionStore
 
 
-def item_group_by_category(items):
-    return sorted(
-        [
-            # a group is a tuple of a category and a list of items
-            (cat, [i for i in items if i.category == cat])
-            for cat in set([i.category for i in items])
-            # insert categories into a set for uniqueness
-            # a set is unsorted, so sort again by category
-        ],
-        key=lambda group: (group[0].position, group[0].id) if (
-            group[0] is not None and group[0].id is not None) else (0, 0)
-    )
-
-
-def get_grouped_items(event, *, channel: SalesChannel, subevent=None, voucher=None, require_seat=0, base_qs=None,
-                      allow_addons=False, allow_cross_sell=False,
-                      quota_cache=None, filter_items=None, filter_categories=None, memberships=None,
-                      ignore_hide_sold_out_for_item_ids=None):
-    base_qs_set = base_qs is not None
-    base_qs = base_qs if base_qs is not None else event.items
-
-    requires_seat = Exists(
-        SeatCategoryMapping.objects.filter(
-            product_id=OuterRef('pk'),
-            subevent=subevent
-        )
-    )
-    if not event.settings.seating_choice:
-        requires_seat = Value(0, output_field=IntegerField())
-
-    variation_q = (
-        Q(Q(available_from__isnull=True) | Q(available_from__lte=time_machine_now()) | Q(available_from_mode='info')) &
-        Q(Q(available_until__isnull=True) | Q(available_until__gte=time_machine_now()) | Q(available_until_mode='info'))
-    )
-    if not voucher or not voucher.show_hidden_items:
-        variation_q &= Q(hide_without_voucher=False)
-
-    if memberships is not None:
-        prefetch_membership_types = ['require_membership_types']
-    else:
-        prefetch_membership_types = []
-
-    prefetch_var = Prefetch(
-        'variations',
-        to_attr='available_variations',
-        queryset=ItemVariation.objects.using(settings.DATABASE_REPLICA).annotate(
-            subevent_disabled=Exists(
-                SubEventItemVariation.objects.filter(
-                    Q(disabled=True)
-                    | (Exact(OuterRef('available_from_mode'), 'hide') & Q(available_from__gt=time_machine_now()))
-                    | (Exact(OuterRef('available_until_mode'), 'hide') & Q(available_until__lt=time_machine_now())),
-                    variation_id=OuterRef('pk'),
-                    subevent=subevent,
-                )
-            ),
-        ).filter(
-            variation_q,
-            Q(all_sales_channels=True) | Q(limit_sales_channels=channel),
-            Exists(Quota.variations.through.objects.filter(quota__subevent_id=subevent, itemvariation_id=OuterRef("pk"))),
-            active=True,
-            subevent_disabled=False
-        ).prefetch_related(
-            *prefetch_membership_types,
-            Prefetch('quotas',
-                     to_attr='_subevent_quotas',
-                     queryset=event.quotas.using(settings.DATABASE_REPLICA).filter(
-                         subevent=subevent).select_related("subevent"))
-        ).distinct()
-    )
-    prefetch_quotas = Prefetch(
-        'quotas',
-        to_attr='_subevent_quotas',
-        queryset=event.quotas.using(settings.DATABASE_REPLICA).filter(subevent=subevent).select_related("subevent")
-    )
-    prefetch_bundles = Prefetch(
-        'bundles',
-        queryset=ItemBundle.objects.using(settings.DATABASE_REPLICA).prefetch_related(
-            Prefetch('bundled_item',
-                     queryset=event.items.using(settings.DATABASE_REPLICA).select_related(
-                         'tax_rule').prefetch_related(
-                         Prefetch('quotas',
-                                  to_attr='_subevent_quotas',
-                                  queryset=event.quotas.using(settings.DATABASE_REPLICA).filter(
-                                      subevent=subevent)),
-                     )),
-            Prefetch('bundled_variation',
-                     queryset=ItemVariation.objects.using(
-                         settings.DATABASE_REPLICA
-                     ).select_related('item', 'item__tax_rule').filter(item__event=event).prefetch_related(
-                         Prefetch('quotas',
-                                  to_attr='_subevent_quotas',
-                                  queryset=event.quotas.using(settings.DATABASE_REPLICA).filter(
-                                      subevent=subevent)),
-                     )),
-        )
-    )
-
-    items = base_qs.using(settings.DATABASE_REPLICA).filter_available(
-        channel=channel.identifier, voucher=voucher, allow_addons=allow_addons, allow_cross_sell=allow_cross_sell
-    ).select_related(
-        'category', 'tax_rule',  # for re-grouping
-        'hidden_if_available',
-    ).prefetch_related(
-        *prefetch_membership_types,
-        Prefetch(
-            'hidden_if_item_available',
-            queryset=event.items.annotate(
-                has_variations=Count('variations'),
-            ).prefetch_related(
-                prefetch_var,
-                prefetch_quotas,
-                prefetch_bundles,
-            )
-        ),
-        prefetch_quotas,
-        prefetch_var,
-        prefetch_bundles,
-    ).annotate(
-        has_variations=Count('variations'),
-        subevent_disabled=Exists(
-            SubEventItem.objects.filter(
-                Q(disabled=True)
-                | (Exact(OuterRef('available_from_mode'), 'hide') & Q(available_from__gt=time_machine_now()))
-                | (Exact(OuterRef('available_until_mode'), 'hide') & Q(available_until__lt=time_machine_now())),
-                item_id=OuterRef('pk'),
-                subevent=subevent,
-            )
-        ),
-        mandatory_priced_addons=Exists(
-            ItemAddOn.objects.filter(
-                base_item_id=OuterRef('pk'),
-                min_count__gte=1,
-                price_included=False
-            )
-        ),
-        requires_seat=requires_seat,
-    ).filter(
-        Exists(Quota.items.through.objects.filter(quota__subevent_id=subevent, item_id=OuterRef("pk"))),
-        subevent_disabled=False,
-    ).order_by('category__position', 'category_id', 'position', 'name')
-    if require_seat:
-        items = items.filter(requires_seat__gt=0)
-    elif require_seat is not None:
-        items = items.filter(requires_seat=0)
-
-    if filter_items:
-        items = items.filter(pk__in=[a for a in filter_items if a.isdigit()])
-    if filter_categories:
-        items = items.filter(category_id__in=[a for a in filter_categories if a.isdigit()])
-
-    display_add_to_cart = False
-    quota_cache_key = f'item_quota_cache:{subevent.id if subevent else 0}:{channel.identifier}:{bool(require_seat)}'
-    quota_cache = quota_cache or event.cache.get(quota_cache_key) or {}
-    quota_cache_existed = bool(quota_cache)
-
-    if subevent:
-        item_price_override = subevent.item_price_overrides
-        var_price_override = subevent.var_price_overrides
-    else:
-        item_price_override = {}
-        var_price_override = {}
-
-    restrict_vars = set()
-    if voucher and voucher.quota_id:
-        # If a voucher is set to a specific quota, we need to filter out on that level
-        restrict_vars = set(voucher.quota.variations.all())
-
-    quotas_to_compute = []
-    for item in items:
-        assert item.event_id == event.pk
-        item.event = event  # save a database query if this is looked up
-        if item.has_variations:
-            for v in item.available_variations:
-                for q in v._subevent_quotas:
-                    if q.pk not in quota_cache:
-                        quotas_to_compute.append(q)
-        else:
-            for q in item._subevent_quotas:
-                if q.pk not in quota_cache:
-                    quotas_to_compute.append(q)
-
-    if quotas_to_compute:
-        qa = QuotaAvailability()
-        qa.queue(*quotas_to_compute)
-        qa.compute()
-        quota_cache.update({q.pk: r for q, r in qa.results.items()})
-
-    for item in items:
-        if voucher and voucher.item_id and voucher.variation_id:
-            # Restrict variations if the voucher only allows one
-            item.available_variations = [v for v in item.available_variations
-                                         if v.pk == voucher.variation_id]
-
-        if channel.type_instance.unlimited_items_per_order:
-            max_per_order = sys.maxsize
-        else:
-            max_per_order = item.max_per_order or int(event.settings.max_items_per_order)
-        if voucher:
-            max_per_order = min(max_per_order, voucher.max_usages - voucher.redeemed)
-
-        if item.hidden_if_available:
-            q = item.hidden_if_available.availability(_cache=quota_cache)
-            if q[0] == Quota.AVAILABILITY_OK:
-                item._remove = True
-                continue
-
-        if item.hidden_if_item_available:
-            if item.hidden_if_item_available.has_variations:
-                item._dependency_available = any(
-                    var.check_quotas(subevent=subevent, _cache=quota_cache, include_bundled=True)[0] == Quota.AVAILABILITY_OK
-                    for var in item.hidden_if_item_available.available_variations
-                )
-            else:
-                q = item.hidden_if_item_available.check_quotas(subevent=subevent, _cache=quota_cache, include_bundled=True)
-                time_available = item.hidden_if_item_available.is_available()
-                item._dependency_available = (q[0] == Quota.AVAILABILITY_OK) and time_available
-            if item._dependency_available and item.hidden_if_item_available_mode == Item.UNAVAIL_MODE_HIDDEN:
-                item._remove = True
-                continue
-
-        if item.require_membership and item.require_membership_hidden:
-            if not memberships or not any([m.membership_type in item.require_membership_types.all() for m in memberships]):
-                item._remove = True
-                continue
-
-        item.current_unavailability_reason = item.unavailability_reason(has_voucher=voucher, subevent=subevent)
-
-        item.description = str(item.description)
-        for recv, resp in item_description.send(sender=event, item=item, variation=None, subevent=subevent):
-            if resp:
-                item.description += ("<br/>" if item.description else "") + resp
-
-        if not item.has_variations:
-            item._remove = False
-            if not bool(item._subevent_quotas):
-                item._remove = True
-                continue
-
-            if voucher and (voucher.allow_ignore_quota or voucher.block_quota):
-                item.cached_availability = (
-                    Quota.AVAILABILITY_OK, voucher.max_usages - voucher.redeemed
-                )
-            else:
-                item.cached_availability = list(
-                    item.check_quotas(subevent=subevent, _cache=quota_cache, include_bundled=True)
-                )
-
-            if not (
-                    ignore_hide_sold_out_for_item_ids and item.pk in ignore_hide_sold_out_for_item_ids
-            ) and event.settings.hide_sold_out and item.cached_availability[0] < Quota.AVAILABILITY_RESERVED:
-                item._remove = True
-                continue
-
-            item.order_max = min(
-                item.cached_availability[1]
-                if item.cached_availability[1] is not None else sys.maxsize,
-                max_per_order
-            )
-
-            original_price = item_price_override.get(item.pk, item.default_price)
-            voucher_reduced = False
-            if voucher:
-                price = voucher.calculate_price(original_price)
-                voucher_reduced = price < original_price
-                include_bundled = not voucher.all_bundles_included
-            else:
-                price = original_price
-                include_bundled = True
-
-            item.display_price = item.tax(price, currency=event.currency, include_bundled=include_bundled)
-            if item.free_price and item.free_price_suggestion is not None and not voucher_reduced:
-                item.suggested_price = item.tax(max(price, item.free_price_suggestion), currency=event.currency, include_bundled=include_bundled)
-            else:
-                item.suggested_price = item.display_price
-
-            if price != original_price:
-                item.original_price = item.tax(original_price, currency=event.currency, include_bundled=True)
-            else:
-                item.original_price = (
-                    item.tax(item.original_price, currency=event.currency, include_bundled=True,
-                             base_price_is='net' if event.settings.display_net_prices else 'gross')  # backwards-compat
-                    if item.original_price else None
-                )
-            if not display_add_to_cart:
-                display_add_to_cart = not item.requires_seat and item.order_max > 0
-        else:
-            for var in item.available_variations:
-                if var.require_membership and var.require_membership_hidden:
-                    if not memberships or not any([m.membership_type in var.require_membership_types.all() for m in memberships]):
-                        var._remove = True
-                        continue
-
-                var.description = str(var.description)
-                for recv, resp in item_description.send(sender=event, item=item, variation=var, subevent=subevent):
-                    if resp:
-                        var.description += ("<br/>" if var.description else "") + resp
-
-                if voucher and (voucher.allow_ignore_quota or voucher.block_quota):
-                    var.cached_availability = (
-                        Quota.AVAILABILITY_OK, voucher.max_usages - voucher.redeemed
-                    )
-                else:
-                    var.cached_availability = list(
-                        var.check_quotas(subevent=subevent, _cache=quota_cache, include_bundled=True)
-                    )
-
-                var.order_max = min(
-                    var.cached_availability[1]
-                    if var.cached_availability[1] is not None else sys.maxsize,
-                    max_per_order
-                )
-
-                original_price = var_price_override.get(var.pk, var.price)
-                voucher_reduced = False
-                if voucher:
-                    price = voucher.calculate_price(original_price)
-                    voucher_reduced = price < original_price
-                    include_bundled = not voucher.all_bundles_included
-                else:
-                    price = original_price
-                    include_bundled = True
-
-                var.display_price = var.tax(price, currency=event.currency, include_bundled=include_bundled)
-
-                if item.free_price and var.free_price_suggestion is not None and not voucher_reduced:
-                    var.suggested_price = item.tax(max(price, var.free_price_suggestion), currency=event.currency,
-                                                   include_bundled=include_bundled)
-                elif item.free_price and item.free_price_suggestion is not None and not voucher_reduced:
-                    var.suggested_price = item.tax(max(price, item.free_price_suggestion), currency=event.currency,
-                                                   include_bundled=include_bundled)
-                else:
-                    var.suggested_price = var.display_price
-
-                if price != original_price:
-                    var.original_price = var.tax(original_price, currency=event.currency, include_bundled=True)
-                else:
-                    var.original_price = (
-                        var.tax(var.original_price or item.original_price, currency=event.currency,
-                                include_bundled=True,
-                                base_price_is='net' if event.settings.display_net_prices else 'gross')  # backwards-compat
-                    ) if var.original_price or item.original_price else None
-
-                var.current_unavailability_reason = var.unavailability_reason(has_voucher=voucher, subevent=subevent)
-
-            item.original_price = (
-                item.tax(item.original_price, currency=event.currency, include_bundled=True,
-                         base_price_is='net' if event.settings.display_net_prices else 'gross')  # backwards-compat
-                if item.original_price else None
-            )
-
-            item.available_variations = [
-                v for v in item.available_variations if v._subevent_quotas and (
-                    not voucher or not voucher.quota_id or v in restrict_vars
-                ) and not getattr(v, '_remove', False)
-            ]
-
-            if not (ignore_hide_sold_out_for_item_ids and item.pk in ignore_hide_sold_out_for_item_ids) and event.settings.hide_sold_out:
-                item.available_variations = [v for v in item.available_variations
-                                             if v.cached_availability[0] >= Quota.AVAILABILITY_RESERVED]
-
-            if voucher and voucher.variation_id:
-                item.available_variations = [v for v in item.available_variations
-                                             if v.pk == voucher.variation_id]
-
-            if len(item.available_variations) > 0:
-                item.min_price = min([v.display_price.net if event.settings.display_net_prices else
-                                      v.display_price.gross for v in item.available_variations])
-                item.max_price = max([v.display_price.net if event.settings.display_net_prices else
-                                      v.display_price.gross for v in item.available_variations])
-                item.best_variation_availability = max([v.cached_availability[0] for v in item.available_variations])
-
-            item._remove = not bool(item.available_variations)
-            if not item._remove and not display_add_to_cart:
-                display_add_to_cart = not item.requires_seat and any(v.order_max > 0 for v in item.available_variations)
-
-    if not quota_cache_existed and not voucher and not allow_addons and not base_qs_set and not filter_items and not filter_categories:
-        event.cache.set(quota_cache_key, quota_cache, 5)
-    items = [item for item in items
-             if (len(item.available_variations) > 0 or not item.has_variations) and not item._remove]
-    return items, display_add_to_cart
-
-
 @method_decorator(allow_frame_if_namespaced, 'dispatch')
 @method_decorator(iframe_entry_view_wrapper, 'dispatch')
 class EventIndex(EventViewMixin, EventListMixin, CartMixin, TemplateView):
@@ -582,7 +196,7 @@ class EventIndex(EventViewMixin, EventListMixin, CartMixin, TemplateView):
 
         if not self.request.event.has_subevents or self.subevent:
             # Fetch all items
-            items, display_add_to_cart = get_grouped_items(
+            items, display_add_to_cart = prepare_item_list_for_shop(
                 self.request.event,
                 subevent=self.subevent,
                 filter_items=self.request.GET.getlist('item'),
@@ -634,10 +248,6 @@ class EventIndex(EventViewMixin, EventListMixin, CartMixin, TemplateView):
         context['has_addon_choices'] = any(cp.has_addon_choices for cp in get_cart(self.request))
 
         templating_context = PlaceholderContext(event_or_subevent=self.subevent or self.request.event, event=self.request.event)
-
-        for field in ('presale_has_ended_text',):
-            context[field] = templating_context.format(str(self.request.event.settings[field]))
-
         if self.subevent:
             context['frontpage_text'] = templating_context.format(str(self.subevent.frontpage_text))
         else:

src/pretix/presale/views/order.py

@@ -79,7 +79,7 @@ from pretix.base.services.invoices import (
 )
 from pretix.base.services.orders import (
     OrderChangeManager, OrderError, _try_auto_refund, cancel_order,
-    change_payment_provider, error_messages,
+    change_payment_provider,
 )
 from pretix.base.services.pricing import get_price
 from pretix.base.services.tickets import generate, invalidate_cache
@@ -92,11 +92,11 @@ from pretix.helpers.safedownload import check_token
 from pretix.multidomain.urlreverse import eventreverse, eventreverse_absolute
 from pretix.presale.forms.checkout import InvoiceAddressForm, QuestionsForm
 from pretix.presale.forms.order import OrderPositionChangeForm
+from pretix.presale.productlist import prepare_item_list_for_shop
 from pretix.presale.signals import question_form_fields_overrides
 from pretix.presale.views import (
     CartMixin, EventViewMixin, iframe_entry_view_wrapper,
 )
-from pretix.presale.views.event import get_grouped_items
 from pretix.presale.views.robots import NoSearchIndexViewMixin
 
 logger = logging.getLogger(__name__)
@@ -1452,7 +1452,7 @@ class OrderChangeMixin:
 
                     if ckey not in item_cache:
                         # Get all items to possibly show
-                        items, _btn = get_grouped_items(
+                        items, _btn = prepare_item_list_for_shop(
                             self.request.event,
                             subevent=p.subevent,
                             voucher=None,
@@ -1592,30 +1592,6 @@ class OrderChangeMixin:
                 if val:
                     selected[i, None] = val, price
 
-        if sum(a[0] for a in selected.values()) > category['max_count']:
-            raise ValidationError(
-                error_messages['addon_max_count'] % {
-                    'base': str(form['pos'].item.name),
-                    'max': category['max_count'],
-                    'cat': str(category['category'].name),
-                }
-            )
-        elif sum(a[0] for a in selected.values()) < category['min_count']:
-            raise ValidationError(
-                error_messages['addon_min_count'] % {
-                    'base': str(form['pos'].item.name),
-                    'min': category['min_count'],
-                    'cat': str(category['category'].name),
-                }
-            )
-        elif any(sum(v[0] for k, v in selected.items() if k[0] == i) > 1 for i in category['items']) and not category['multi_allowed']:
-            raise ValidationError(
-                error_messages['addon_no_multi'] % {
-                    'base': str(form['pos'].item.name),
-                    'cat': str(category['category'].name),
-                }
-            )
-
         return selected
 
     def post(self, request, *args, **kwargs):

src/pretix/presale/views/waiting.py

@@ -40,8 +40,8 @@ from pretix.presale.views import EventViewMixin, iframe_entry_view_wrapper
 from ...base.i18n import get_language_without_region
 from ...base.models import Voucher, WaitingListEntry
 from ..forms.waitinglist import WaitingListForm
+from ..productlist import prepare_item_list_for_shop
 from . import allow_frame_if_namespaced
-from .event import get_grouped_items
 
 
 @method_decorator(allow_frame_if_namespaced, 'dispatch')
@@ -53,7 +53,7 @@ class WaitingView(EventViewMixin, FormView):
     @cached_property
     def itemvars(self):
         customer = getattr(self.request, 'customer', None)
-        items, display_add_to_cart = get_grouped_items(
+        items, display_add_to_cart = prepare_item_list_for_shop(
             self.request.event,
             subevent=self.subevent,
             require_seat=None,

src/pretix/presale/views/widget.py

@@ -67,11 +67,11 @@ from pretix.helpers.daterange import daterange
 from pretix.helpers.thumb import get_thumbnail
 from pretix.multidomain.urlreverse import eventreverse_absolute
 from pretix.presale.forms.organizer import meta_filtersets
+from pretix.presale.productlist import (
+    item_group_by_category, prepare_item_list_for_shop,
+)
 from pretix.presale.style import get_theme_vars_css
 from pretix.presale.views.cart import get_or_create_cart_id
-from pretix.presale.views.event import (
-    get_grouped_items, item_group_by_category,
-)
 from pretix.presale.views.organizer import (
     EventListMixin, add_events_for_days, add_subevents_for_days,
     days_for_template, filter_qs_by_attr, filter_subevents_with_plugins,
@@ -324,7 +324,7 @@ class WidgetAPIProductList(EventListMixin, View):
                 ).values_list('item_id', flat=True)
             )
 
-        items, display_add_to_cart = get_grouped_items(
+        items, display_add_to_cart = prepare_item_list_for_shop(
             self.request.event,
             subevent=self.subevent,
             voucher=self.voucher,

src/tests/presale/test_order_change.py

@@ -994,7 +994,7 @@ class OrderChangeAddonsTest(BaseOrdersTest):
             self.order.refresh_from_db()
             assert self.order.total == Decimal('23.00')
 
-    def test_do_not_remove_unavailable_on_adding(self):
+    def test_do_not_remove_timeunavailable_on_adding(self):
         self.iao.max_count = 2
         self.iao.save()
         self.workshop1.available_until = now() - datetime.timedelta(days=1)
@@ -1036,6 +1036,48 @@ class OrderChangeAddonsTest(BaseOrdersTest):
         with scopes_disabled():
             assert self.ticket_pos.addons.count() == 2
 
+    def test_do_not_remove_dependencyunavailable_on_adding(self):
+        self.iao.max_count = 2
+        self.iao.save()
+        self.workshop1.hidden_if_item_available = self.workshop2
+        self.workshop1.save()
+        with scopes_disabled():
+            OrderPosition.objects.create(
+                order=self.order,
+                item=self.workshop1,
+                variation=None,
+                price=Decimal("12"),
+                addon_to=self.ticket_pos,
+                attendee_name_parts={'full_name': "Peter"}
+            )
+            self.order.total += Decimal("12")
+            self.order.save()
+
+        response = self.client.get(
+            '/%s/%s/order/%s/%s/change' % (self.orga.slug, self.event.slug, self.order.code, self.order.secret)
+        )
+        assert response.status_code == 200
+        assert '<li>1x Workshop 1</li>' in response.content.decode()
+        assert f'cp_{self.ticket_pos.pk}_item_{self.workshop1.pk}' not in response.content.decode()
+
+        response = self.client.post(
+            '/%s/%s/order/%s/%s/change' % (self.orga.slug, self.event.slug, self.order.code, self.order.secret),
+            {
+                f'cp_{self.ticket_pos.pk}_variation_{self.workshop2.pk}_{self.workshop2a.pk}': '1'
+            },
+            follow=True
+        )
+        doc = BeautifulSoup(response.content.decode(), "lxml")
+        form_data = extract_form_fields(doc.select('.main-box form')[0])
+        form_data['confirm'] = 'true'
+        response = self.client.post(
+            '/%s/%s/order/%s/%s/change' % (self.orga.slug, self.event.slug, self.order.code, self.order.secret), form_data, follow=True
+        )
+        assert 'alert-success' in response.content.decode()
+
+        with scopes_disabled():
+            assert self.ticket_pos.addons.count() == 2
+
     def test_do_not_overbook_unavailable_on_adding(self):
         self.iao.max_count = 1
         self.iao.save()