Improve add-on products

src/pretix/control/forms/event.py

@@ -257,7 +257,8 @@ class EventSettingsForm(SettingsForm):
     )
     max_items_per_order = forms.IntegerField(
         min_value=1,
-        label=_("Maximum number of items per order")
+        label=_("Maximum number of items per order"),
+        help_text=_("Add-on products will not be counted.")
     )
     reservation_time = forms.IntegerField(
         min_value=0,
@@ -607,6 +608,10 @@ class TicketSettingsForm(SettingsForm):
         required=True,
         widget=forms.DateTimeInput(attrs={'class': 'datetimepicker'})
     )
+    ticket_download_addons = forms.BooleanField(
+        label=_("Offer to download tickets separately for add-on products"),
+        required=False
+    )
 
     def prepare_fields(self):
         # See clean()

src/pretix/control/forms/item.py

@@ -265,3 +265,7 @@ class ItemAddOnForm(I18nModelForm):
             'min_count',
             'max_count',
         ]
+        help_texts = {
+            'min_count': _('Be aware that setting a minimal number makes it impossible to buy this product if all '
+                           'available add-ons are sold out.')
+        }

src/pretix/control/forms/vouchers.py

@@ -76,6 +76,9 @@ class VoucherForm(I18nModelForm):
             else:
                 self.instance.variation = None
             self.instance.quota = None
+
+            if self.instance.item.category and self.instance.item.category.is_addon:
+                raise ValidationError(_('It is currently not possible to create vouchers for add-on products.'))
         else:
             self.instance.quota = Quota.objects.get(pk=quotaid, event=self.instance.event)
             self.instance.item = None