Don't automatically commit model when adding/removing multi subreddits.

r2/r2/controllers/multi.py

@@ -143,6 +143,8 @@ class MultiApiController(RedditController, OAuth2ResourceController):
             multi.add_srs({sr._id: {}})
         except TooManySubredditsException as e:
             raise RedditError('MULTI_TOO_MANY_SUBREDDITS', code=409)
+        else:
+            multi._commit()
 
     @require_oauth2_scope("subscribe")
     @api_doc(api_section.multis, extends=PUT_multi_subreddit)
@@ -155,3 +157,4 @@ class MultiApiController(RedditController, OAuth2ResourceController):
     def DELETE_multi_subreddit(self, multi, sr):
         """Remove a subreddit from a multi."""
         multi.del_srs(sr._id)
+        multi._commit()

r2/r2/models/subreddit.py

@@ -1442,7 +1442,6 @@ class LabeledMulti(tdb_cassandra.Thing, MultiReddit):
 
         for attr, val in sr_columns.iteritems():
             self.__setattr__(attr, val)
-        self._commit()
 
     def del_srs(self, sr_ids):
         """Delete subreddit(s)."""
@@ -1450,7 +1449,6 @@ class LabeledMulti(tdb_cassandra.Thing, MultiReddit):
         keys = self.sr_props_to_columns(dict.fromkeys(sr_ids, '')).keys()
         for key in keys:
             self.__delitem__(key)
-        self._commit()
 
     def delete(self):
         # Do we want to actually delete objects?