[wip] Add migration to activate plugin, add plugin active check before run (23243588)

src/pretix/plugins/sendmail/migrations/0013_activate_plugin_for_events_with_scheduled_mails.py

@@ -0,0 +1,29 @@
+from django.db import migrations
+from django.db.models import Exists, OuterRef
+
+
+def activate_plugin(apps, schema_editor):
+    Event = apps.get_model("pretixbase", "Event")
+    ScheduledMail = apps.get_model("sendmail", "ScheduledMail")
+    events = (
+        Event.objects
+        .exclude(plugins__icontains="pretix.plugins.sendmail")
+        .filter(
+            Exists(
+                ScheduledMail.objects.filter(event=OuterRef('pk')).exclude(state=ScheduledMail.STATE_COMPLETED)
+            )
+        )
+    )
+    for event in events:
+        event.enable_plugin('pretix.plugins.sendmail')
+        event.save(update_fields=['plugins'])
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("sendmail", "0012_remove_cross_event_scheduled_mails"),
+    ]
+
+    operations = [
+        migrations.RunPython(activate_plugin),
+    ]

src/pretix/plugins/sendmail/signals.py

@@ -150,6 +150,8 @@ class SendmailPluginRuleLogEntryType(EventLogEntryType):
 
 @receiver(periodic_task)
 def sendmail_run_rules(sender, **kwargs):
+    if "pretix.plugins.sendmail" not in sender.get_plugins():
+        return  # do not send scheduled mails if this plugin is disabled
     with scopes_disabled():
         mails = ScheduledMail.objects.all()