diff options
| -rw-r--r-- | synapse/handlers/presence.py | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/synapse/handlers/presence.py b/synapse/handlers/presence.py index 5204073a38..3edd359985 100644 --- a/synapse/handlers/presence.py +++ b/synapse/handlers/presence.py @@ -1017,11 +1017,21 @@ class PresenceEventSource(object): if from_key is not None: from_key = int(from_key) + max_token = self.store.get_current_presence_token() + if from_key == max_token: + # This is necessary as due to the way stream ID generators work + # we may get updates that have a stream ID greater than the max + # token. This is usually fine, as it just means that we may send + # down some presence updates multiple times. However, we need to + # be careful that the sync stream actually does make some + # progress, otherwise clients will end up tight looping calling + # /sync due to it returning the same token repeatedly. Hence + # this guard. C.f. #5503. + defer.returnValue(([], max_token)) + presence = self.get_presence_handler() stream_change_cache = self.store.presence_stream_cache - max_token = self.store.get_current_presence_token() - users_interested_in = yield self._get_interested_in(user, explicit_room_id) user_ids_changed = set() |