Clarify cart order (#2844)

src/pretix/base/models/orders.py

@@ -2237,7 +2237,7 @@ class OrderPosition(AbstractPosition):
 
     @cached_property
     def sort_key(self):
-        return self.addon_to.positionid if self.addon_to else self.positionid, self.addon_to_id or 0
+        return self.addon_to.positionid if self.addon_to else self.positionid, self.addon_to_id or 0, self.positionid
 
     @property
     def checkins(self):
@@ -2263,7 +2263,7 @@ class OrderPosition(AbstractPosition):
         ops = []
         cp_mapping = {}
         # The sorting key ensures that all addons come directly after the position they refer to
-        for i, cartpos in enumerate(sorted(cp, key=lambda c: (c.addon_to_id or c.pk, c.addon_to_id or 0))):
+        for i, cartpos in enumerate(sorted(cp, key=lambda c: c.sort_key)):
             op = OrderPosition(order=order)
             for f in AbstractPosition._meta.fields:
                 if f.name == 'addon_to':
@@ -2659,6 +2659,20 @@ class CartPosition(AbstractPosition):
                             self.event.currency)
         return self.price - net
 
+    @cached_property
+    def sort_key(self):
+        subevent_key = (self.subevent.date_from, str(self.subevent.name), self.subevent_id) if self.subevent_id else (0, "", 0)
+        category_key = (self.item.category.position, self.item.category.id) if self.item.category_id is not None else (0, 0)
+        item_key = self.item.position, self.item_id
+        variation_key = (self.variation.position, self.variation.id) if self.variation_id is not None else (0, 0)
+        line_key = (self.price, (self.voucher_id or 0), (self.seat.sorting_rank if self.seat_id else None), self.pk)
+        sort_key = subevent_key + category_key + item_key + variation_key + line_key
+
+        if self.addon_to_id:
+            return self.addon_to.sort_key + (1 if self.is_bundled else 2,) + sort_key
+        else:
+            return sort_key
+
     def update_listed_price_and_voucher(self, voucher_only=False, max_discount=None):
         from pretix.base.services.pricing import (
             get_listed_price, is_included_for_free,
@@ -2716,7 +2730,8 @@ class CartPosition(AbstractPosition):
 
     @property
     def addons_without_bundled(self):
-        return [op for op in self.addons.all() if not op.is_bundled]
+        addons = [op for op in self.addons.all() if not op.is_bundled]
+        return sorted(addons, key=lambda cp: cp.sort_key)
 
 
 class InvoiceAddress(models.Model):

src/pretix/base/views/mixins.py

@@ -44,16 +44,6 @@ class BaseQuestionsViewMixin:
     form_class = BaseQuestionsForm
     all_optional = False
 
-    @staticmethod
-    def _keyfunc(pos):
-        # Sort addons after the item they are an addon to
-        if isinstance(pos, OrderPosition):
-            i = pos.addon_to.positionid if pos.addon_to else pos.positionid
-        else:
-            i = pos.addon_to.pk if pos.addon_to else pos.pk
-        addon_penalty = 1 if pos.addon_to else 0
-        return i, addon_penalty, pos.pk
-
     @cached_property
     def _positions_for_questions(self):
         raise NotImplementedError()

src/pretix/presale/checkoutflow.py

@@ -497,9 +497,9 @@ class AddOnsStep(CartMixin, AsyncAction, TemplateFlowStep):
         formset = []
         quota_cache = {}
         item_cache = {}
-        for cartpos in get_cart(self.request).filter(addon_to__isnull=True).prefetch_related(
+        for cartpos in sorted(get_cart(self.request).filter(addon_to__isnull=True).prefetch_related(
             'item__addons', 'item__addons__addon_category', 'addons', 'addons__variation',
-        ).order_by('pk'):
+        ), key=lambda c: c.sort_key):
             formsetentry = {
                 'pos': cartpos,
                 'item': cartpos.item,

src/pretix/presale/views/__init__.py

@@ -35,7 +35,7 @@
 from collections import defaultdict
 from datetime import datetime, timedelta
 from decimal import Decimal
-from functools import partial, wraps
+from functools import wraps
 from itertools import groupby
 
 from django.conf import settings
@@ -46,7 +46,7 @@ from django_scopes import scopes_disabled
 
 from pretix.base.i18n import language
 from pretix.base.models import (
-    CartPosition, Customer, InvoiceAddress, ItemAddOn, OrderPosition, Question,
+    CartPosition, Customer, InvoiceAddress, ItemAddOn, Question,
     QuestionAnswer, QuestionOption,
 )
 from pretix.base.services.cart import get_fees
@@ -145,57 +145,32 @@ class CartMixin:
         # Group items of the same variation
         # We do this by list manipulations instead of a GROUP BY query, as
         # Django is unable to join related models in a .values() query
-        def keyfunc(pos, for_sorting=False):
-            if isinstance(pos, OrderPosition):
-                if pos.addon_to_id:
-                    i = pos.addon_to.positionid
-                else:
-                    i = pos.positionid
-            else:
-                if pos.addon_to_id:
-                    i = pos.addon_to_id
-                else:
-                    i = pos.pk
-
+        def group_key(pos):  # only used for grouping, sorting is done before already
             has_attendee_data = pos.item.admission and (
                 self.request.event.settings.attendee_names_asked
                 or self.request.event.settings.attendee_emails_asked
+                or self.request.event.settings.attendee_company_asked
+                or self.request.event.settings.attendee_addresses_asked
                 or pos_additional_fields.get(pos.pk)
             )
+            grouping_allowed = (
+                # Never group when we have per-ticket download buttons
+                not downloads and
+                # Never group if the position has add-ons
+                pos.pk not in has_addons and
+                # Never group if we have answers to show
+                (not answers or (not has_attendee_data and not bool(pos.item.questions.all()))) and  # do not use .exists() to re-use prefetch cache
+                # Never group when we have a final order and a gift card code
+                (isinstance(pos, CartPosition) or not pos.item.issue_giftcard)
+            )
 
-            addon_penalty = 1 if pos.addon_to_id else 0
-
-            if downloads \
-                    or pos.pk in has_addons \
-                    or pos.item.issue_giftcard \
-                    or (answers and (has_attendee_data or bool(pos.item.questions.all()))):  # do not use .exists() to re-use prefetch cache
-                return (
-                    # standalone positions are grouped by main product position id, addons below them also sorted by position id
-                    i, addon_penalty, pos.positionid if isinstance(pos, OrderPosition) else pos.pk,
-                    # all other places are only used for positions that can be grouped. We just put zeros.
-                ) + (0, ) * 12
-
-            # positions are sorted and grouped by various attributes
-            category_key = (pos.item.category.position, pos.item.category.id) if pos.item.category is not None else (0, 0)
-            item_key = pos.item.position, pos.item_id
-            variation_key = (pos.variation.position, pos.variation.id) if pos.variation is not None else (0, 0)
-            subevent_key = (pos.subevent.date_from, str(pos.subevent.name), pos.subevent_id) if pos.subevent_id else (0, "", 0)
-            grp = subevent_key + category_key + item_key + variation_key + (pos.price, (pos.voucher_id or 0), (pos.seat_id or 0))
-            if pos.addon_to_id:
-                if for_sorting:
-                    ii = pos.positionid if isinstance(pos, OrderPosition) else pos.pk
-                else:
-                    ii = 0
-                return (
-                    i, addon_penalty, ii,
-                ) + grp
-            return (
-                # These are grouped by attributes so we don't put any position ids
-                0, 0, 0,
-            ) + grp
+            if not grouping_allowed:
+                return (pos.pk,) + (0, ) * 6
+            else:
+                return (pos.addon_to_id or 0), pos.subevent_id, pos.item_id, pos.variation_id, pos.price, (pos.voucher_id or 0), (pos.seat_id or 0)
 
         positions = []
-        for k, g in groupby(sorted(lcp, key=partial(keyfunc, for_sorting=True)), key=keyfunc):
+        for k, g in groupby(sorted(lcp, key=lambda c: c.sort_key), key=group_key):
             g = list(g)
             group = g[0]
             group.count = len(g)
@@ -291,7 +266,7 @@ def get_cart(request):
                 'item__category__position', 'item__category_id', 'item__position', 'item__name', 'variation__value'
             ).select_related(
                 'item', 'variation', 'subevent', 'subevent__event', 'subevent__event__organizer',
-                'item__tax_rule', 'addon_to', 'used_membership', 'used_membership__membership_type'
+                'item__tax_rule', 'item__category', 'used_membership', 'used_membership__membership_type'
             ).select_related(
                 'addon_to'
             ).prefetch_related(
@@ -312,8 +287,12 @@ def get_cart(request):
                          ).select_related('dependency_question'),
                          to_attr='questions_to_ask')
             )
+            by_id = {cp.pk: cp for cp in request._cart_cache}
             for cp in request._cart_cache:
-                cp.event = request.event  # Populate field with known value to save queries
+                # Populate fields with known values to save queries
+                cp.event = request.event
+                if cp.addon_to_id:
+                    cp.addon_to = by_id[cp.addon_to_id]
     return request._cart_cache
 
 

src/pretix/presale/views/questions.py

@@ -46,7 +46,7 @@ class QuestionsViewMixin(BaseQuestionsViewMixin):
     @cached_property
     def _positions_for_questions(self):
         cart = get_cart(self.request)
-        return sorted(list(cart), key=self._keyfunc)
+        return sorted(list(cart), key=lambda cp: cp.sort_key)
 
     def question_form_kwargs(self, cr):
         d = {