Event product list: Hotfix for pathological performance in large event series (#6318)

* Event product list: Hotfix for pathological performance

* Stop outputting bullsht numbers to widget

src/pretix/presale/views/event.py

@@ -215,7 +215,6 @@ def get_grouped_items(event, *, channel: SalesChannel, subevent=None, voucher=No
         prefetch_var,
         prefetch_bundles,
     ).annotate(
-        quotac=Count('quotas'),
         has_variations=Count('variations'),
         subevent_disabled=Exists(
             SubEventItem.objects.filter(
@@ -235,7 +234,8 @@ def get_grouped_items(event, *, channel: SalesChannel, subevent=None, voucher=No
         ),
         requires_seat=requires_seat,
     ).filter(
-        quotac__gt=0, subevent_disabled=False,
+        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)

src/pretix/presale/views/widget.py

@@ -352,7 +352,7 @@ class WidgetAPIProductList(EventListMixin, View):
                         'picture': get_picture(self.request.event, item.picture, '60x60^') if item.picture else None,
                         'picture_fullsize': get_picture(self.request.event, item.picture) if item.picture else None,
                         'description': str(rich_text(item.description, safelinks=False)) if item.description else None,
-                        'has_variations': item.has_variations,
+                        'has_variations': bool(item.has_variations),
                         'current_unavailability_reason': item.current_unavailability_reason,
                         'order_min': item.min_per_order,
                         'order_max': item.order_max if not item.has_variations else None,