Remove double return statements (#5962)

Remove all the "double return" statements which were a result of us removing all the instances of

```
defer.returnValue(...)
return
```

statements when we switched to python3 fully.

changelog.d/5962.misc

@@ -0,0 +1 @@
+Remove unnecessary return statements in the codebase which were the result of a regex run.

synapse/api/auth.py

@@ -704,7 +704,6 @@ class Auth(object):
                 and visibility.content["history_visibility"] == "world_readable"
             ):
                 return Membership.JOIN, None
-                return
             raise AuthError(
                 403, "Guest access not allowed", errcode=Codes.GUEST_ACCESS_FORBIDDEN
             )

synapse/appservice/api.py

@@ -107,7 +107,6 @@ class ApplicationServiceApi(SimpleHttpClient):
         except CodeMessageException as e:
             if e.code == 404:
                 return False
-                return
             logger.warning("query_user to %s received %s", uri, e.code)
         except Exception as ex:
             logger.warning("query_user to %s threw exception %s", uri, ex)
@@ -127,7 +126,6 @@ class ApplicationServiceApi(SimpleHttpClient):
             logger.warning("query_alias to %s received %s", uri, e.code)
             if e.code == 404:
                 return False
-                return
         except Exception as ex:
             logger.warning("query_alias to %s threw exception %s", uri, ex)
         return False
@@ -230,7 +228,6 @@ class ApplicationServiceApi(SimpleHttpClient):
             sent_transactions_counter.labels(service.id).inc()
             sent_events_counter.labels(service.id).inc(len(events))
             return True
-            return
         except CodeMessageException as e:
             logger.warning("push_bulk to %s received %s", uri, e.code)
         except Exception as ex:

synapse/handlers/appservice.py

@@ -294,12 +294,10 @@ class ApplicationServicesHandler(object):
             # we don't know if they are unknown or not since it isn't one of our
             # users. We can't poke ASes.
             return False
-            return
 
         user_info = yield self.store.get_user_by_id(user_id)
         if user_info:
             return False
-            return
 
         # user not found; could be the AS though, so check.
         services = self.store.get_app_services()

synapse/handlers/events.py

@@ -167,7 +167,6 @@ class EventHandler(BaseHandler):
 
         if not event:
             return None
-            return
 
         users = yield self.store.get_users_in_room(event.room_id)
         is_peeking = user.to_string() not in users

synapse/handlers/initial_sync.py

@@ -450,7 +450,6 @@ class InitialSyncHandler(BaseHandler):
             # else it will throw.
             member_event = yield self.auth.check_user_was_in_room(room_id, user_id)
             return member_event.membership, member_event.event_id
-            return
         except AuthError:
             visibility = yield self.state_handler.get_current_state(
                 room_id, EventTypes.RoomHistoryVisibility, ""
@@ -460,7 +459,6 @@ class InitialSyncHandler(BaseHandler):
                 and visibility.content["history_visibility"] == "world_readable"
             ):
                 return Membership.JOIN, None
-                return
             raise AuthError(
                 403, "Guest access not allowed", errcode=Codes.GUEST_ACCESS_FORBIDDEN
             )

synapse/handlers/room.py

@@ -852,7 +852,6 @@ class RoomContextHandler(object):
         )
         if not event:
             return None
-            return
 
         filtered = yield (filter_evts([event]))
         if not filtered:

synapse/handlers/sync.py

@@ -578,7 +578,6 @@ class SyncHandler(object):
 
         if not last_events:
             return None
-            return
 
         last_event = last_events[-1]
         state_ids = yield self.store.get_state_ids_for_event(

synapse/rest/client/v1/room.py

@@ -703,7 +703,6 @@ class RoomMembershipRestServlet(TransactionRestServlet):
                 txn_id,
             )
             return 200, {}
-            return
 
         target = requester.user
         if membership_action in ["invite", "ban", "unban", "kick"]:

synapse/rest/client/v2_alpha/register.py

@@ -230,7 +230,6 @@ class RegisterRestServlet(RestServlet):
         if kind == b"guest":
             ret = yield self._do_guest_registration(body, address=client_addr)
             return ret
-            return
         elif kind != b"user":
             raise UnrecognizedRequestError(
                 "Do not understand membership kind: %s" % (kind,)
@@ -280,7 +279,6 @@ class RegisterRestServlet(RestServlet):
                     desired_username, access_token, body
                 )
             return 200, result  # we throw for non 200 responses
-            return
 
         # for regular registration, downcase the provided username before
         # attempting to register it. This should mean

synapse/rest/media/v1/preview_url_resource.py

@@ -183,7 +183,6 @@ class PreviewUrlResource(DirectServeResource):
             if isinstance(og, six.text_type):
                 og = og.encode("utf8")
             return og
-            return
 
         media_info = yield self._download_url(url, user)
 

synapse/state/__init__.py

@@ -136,7 +136,6 @@ class StateHandler(object):
             if event_id:
                 event = yield self.store.get_event(event_id, allow_none=True)
             return event
-            return
 
         state_map = yield self.store.get_events(
             list(state.values()), get_prev_content=False

synapse/storage/appservice.py

@@ -165,7 +165,6 @@ class ApplicationServiceTransactionWorkerStore(
         )
         if result:
             return result.get("state")
-            return
         return None
 
     def set_appservice_state(self, service, state):

synapse/storage/directory.py

@@ -47,7 +47,6 @@ class DirectoryWorkerStore(SQLBaseStore):
 
         if not room_id:
             return None
-            return
 
         servers = yield self._simple_select_onecol(
             "room_alias_servers",
@@ -58,7 +57,6 @@ class DirectoryWorkerStore(SQLBaseStore):
 
         if not servers:
             return None
-            return
 
         return RoomAliasMapping(room_id, room_alias.to_string(), servers)
 

synapse/storage/profile.py

@@ -35,7 +35,6 @@ class ProfileWorkerStore(SQLBaseStore):
             if e.code == 404:
                 # no match
                 return ProfileInfo(None, None)
-                return
             else:
                 raise