No need to iterate over the categories if the user isn't tracking them

Author: alexiri

outlook/indico_outlook/plugin.py

@@ -318,13 +318,14 @@ def event_updated(self, event, changes, **kwargs):
             if self._user_tracks_favorite_events(user):
                 users_to_update.add(user)
 
-        for category in reversed(event.category.chain_query.all()):
-            for user in category.favorite_of:
-                if self._user_tracks_favorite_categories(user) and event.can_access(user):
-                    users_to_update.add(user)
-            # Stop once we reach the visibility horizon of the event
-            if category is event.category.real_visibility_horizon:
-                break
+        if self._user_tracks_favorite_categories(user):
+            for category in reversed(event.category.chain_query.all()):
+                for user in category.favorite_of:
+                    if event.can_access(user):
+                        users_to_update.add(user)
+                # Stop once we reach the visibility horizon of the event
+                if category is event.category.real_visibility_horizon:
+                    break
 
         for user in users_to_update:
             self.logger.info('Event data change: updating %s in %r', user, event)