mark_order_paid: Only lock when necessary

src/pretix/base/models/orders.py

@@ -279,12 +279,13 @@ class Order(LoggedModel):
 
             if now() > last_date:
                 return error_messages['late']
-        if self.status == self.STATUS_PENDING:
-            return True
         if not self.event.settings.get('payment_term_accept_late'):
             return error_messages['late']
 
-        return self._is_still_available()
+        if self.status == self.STATUS_PENDING:
+            return True
+        else:
+            return self._is_still_available()
 
     def _is_still_available(self, now_dt: datetime=None) -> Union[bool, str]:
         error_messages = {

src/pretix/base/services/orders.py

@@ -82,7 +82,14 @@ def mark_order_paid(order: Order, provider: str=None, info: str=None, date: date
     :param user: The user that performed the change
     :raises Quota.QuotaExceededException: if the quota is exceeded and ``force`` is ``False``
     """
-    with order.event.lock() as now_dt:
+    lock_func = order.event.lock
+    if order.status == order.STATUS_PENDING and order.expires > now() + timedelta(minutes=10):
+        # No lock necessary in this case. The 10 minute offset is just to be safe and prevent
+        # collisions with the cronjob.
+        def lock_func():
+            return now()
+
+    with lock_func() as now_dt:
         can_be_paid = order._can_be_paid()
         if not force and can_be_paid is not True:
             raise Quota.QuotaExceededException(can_be_paid)