Let plugins prevent the download of individual tickets in an order (#3858)

* Let plugins allow/prevent the download of individual tickets in an order (#3836)

(extends the functionality of the allow_ticket_download signal)

(cherry picked from commit e20edab98f)

* fix bug where in some cases, only the first ticket could be downloaded

src/tests/base/test_orders.py

@@ -55,6 +55,7 @@ from pretix.base.services.orders import (
     send_expiry_warnings,
 )
 from pretix.plugins.banktransfer.payment import BankTransfer
+from pretix.testutils.mock import mocker_context
 from pretix.testutils.scope import classscope
 
 
@@ -820,7 +821,7 @@ class DownloadReminderTests(TestCase):
             self.event = Event.objects.create(
                 organizer=self.o, name='Dummy', slug='dummy',
                 date_from=now() + timedelta(days=2),
-                plugins='pretix.plugins.banktransfer'
+                plugins='pretix.plugins.banktransfer,tests.testdummy'
             )
             self.order = Order.objects.create(
                 code='FOO', event=self.event, email='dummy@dummy.test',
@@ -853,6 +854,58 @@ class DownloadReminderTests(TestCase):
         send_download_reminders(sender=self.event)
         assert len(djmail.outbox) == 0
 
+    @classscope(attr='o')
+    def test_downloads_disabled_by_plugin(self):
+        with mocker_context() as mocker:
+            self.event.settings.mail_days_download_reminder = 2
+
+            from pretix.base.signals import allow_ticket_download
+            mocker.patch('pretix.base.signals.allow_ticket_download.send')
+            allow_ticket_download.send.return_value = [(None, [])]
+
+            send_download_reminders(sender=self.event)
+            assert len(djmail.outbox) == 0
+
+    @classscope(attr='o')
+    def test_downloads_all_allowed_by_plugin(self):
+        with mocker_context() as mocker:
+            self.event.settings.mail_days_download_reminder = 2
+            self.event.settings.mail_attach_tickets = True
+            self.event.settings.ticketoutput_testdummy__enabled = True
+
+            self.op2 = OrderPosition.objects.create(
+                order=self.order, item=self.ticket, variation=None,
+                price=Decimal("42.00"), attendee_name_parts={"full_name": "Mary"}, positionid=2
+            )
+
+            from pretix.base.signals import allow_ticket_download
+            mocker.patch('pretix.base.signals.allow_ticket_download.send')
+            allow_ticket_download.send.return_value = [(None, True)]
+
+            send_download_reminders(sender=self.event)
+            assert len(djmail.outbox) == 1
+            assert len(djmail.outbox[0].attachments) == 2
+
+    @classscope(attr='o')
+    def test_downloads_partially_disabled_by_plugin(self):
+        with mocker_context() as mocker:
+            self.event.settings.mail_days_download_reminder = 2
+            self.event.settings.mail_attach_tickets = True
+            self.event.settings.ticketoutput_testdummy__enabled = True
+
+            self.op2 = OrderPosition.objects.create(
+                order=self.order, item=self.ticket, variation=None,
+                price=Decimal("42.00"), attendee_name_parts={"full_name": "Mary"}, positionid=2
+            )
+
+            from pretix.base.signals import allow_ticket_download
+            mocker.patch('pretix.base.signals.allow_ticket_download.send')
+            allow_ticket_download.send.return_value = [(None, [self.op2])]
+
+            send_download_reminders(sender=self.event)
+            assert len(djmail.outbox) == 1
+            assert len(djmail.outbox[0].attachments) == 1
+
     @classscope(attr='o')
     def test_disabled(self):
         send_download_reminders(sender=self.event)

src/tests/testdummy/ticketoutput.py

@@ -33,3 +33,7 @@ class DummyTicketOutput(BaseTicketOutput):
 
     def generate(self, op):
         return 'test.txt', 'text/plain', str(op.order.id)
+
+    @property
+    def multi_download_enabled(self) -> bool:
+        return False