Ignore event end date for subevents

src/pretix/base/models/event.py

@@ -268,6 +268,13 @@ class Event(EventMixin, LoggedModel):
     def __str__(self):
         return str(self.name)
 
+    @property
+    def presale_has_ended(self):
+        if self.has_subevents:
+            return self.presale_end and now() > self.presale_end
+        else:
+            return super().presale_has_ended
+
     def save(self, *args, **kwargs):
         obj = super().save(*args, **kwargs)
         self.cache.clear()

src/pretix/base/services/cart.py

@@ -188,7 +188,7 @@ class CartManager:
             if op.subevent and op.subevent.presale_start and self.now_dt < op.subevent.presale_start:
                 raise CartError(error_messages['not_started'])
 
-            if op.subevent and op.subevent.presale_end and self.now_dt > op.subevent.presale_end:
+            if op.subevent and op.subevent.presale_has_ended:
                 raise CartError(error_messages['ended'])
 
         if isinstance(op, self.AddOperation):

src/pretix/base/services/orders.py

@@ -361,7 +361,7 @@ def _check_positions(event: Event, now_dt: datetime, positions: List[CartPositio
             cp.delete()
             break
 
-        if cp.subevent and cp.subevent.presale_end and now_dt > cp.subevent.presale_end:
+        if cp.subevent and cp.subevent.presale_has_ended:
             err = err or error_messages['some_subevent_ended']
             cp.delete()
             break