diff options
| -rw-r--r-- | changelog.d/15383.bugfix | 1 | ||||
| -rw-r--r-- | synapse/handlers/sync.py | 24 |
2 files changed, 20 insertions, 5 deletions
diff --git a/changelog.d/15383.bugfix b/changelog.d/15383.bugfix new file mode 100644 index 0000000000..28c66ef454 --- /dev/null +++ b/changelog.d/15383.bugfix @@ -0,0 +1 @@ +Fix a rare bug introduced in Synapse 1.66.0 where initial syncs would fail when the user had been kicked from a faster joined room that had not finished syncing. diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py index 9f5b83ed54..64d298408d 100644 --- a/synapse/handlers/sync.py +++ b/synapse/handlers/sync.py @@ -943,6 +943,8 @@ class SyncHandler: timeline_state = {} + # Membership events to fetch that can be found in the room state, or in + # the case of partial state rooms, the auth events of timeline events. members_to_fetch = set() first_event_by_sender_map = {} for event in batch.events: @@ -964,9 +966,19 @@ class SyncHandler: # (if we are) to fix https://github.com/vector-im/riot-web/issues/7209 # We only need apply this on full state syncs given we disabled # LL for incr syncs in #3840. - members_to_fetch.add(sync_config.user.to_string()) - - state_filter = StateFilter.from_lazy_load_member_list(members_to_fetch) + # We don't insert ourselves into `members_to_fetch`, because in some + # rare cases (an empty event batch with a now_token after the user's + # leave in a partial state room which another local user has + # joined), the room state will be missing our membership and there + # is no guarantee that our membership will be in the auth events of + # timeline events when the room is partial stated. + state_filter = StateFilter.from_lazy_load_member_list( + members_to_fetch.union((sync_config.user.to_string(),)) + ) + else: + state_filter = StateFilter.from_lazy_load_member_list( + members_to_fetch + ) # We are happy to use partial state to compute the `/sync` response. # Since partial state may not include the lazy-loaded memberships we @@ -988,7 +1000,9 @@ class SyncHandler: # sync's timeline and the start of the current sync's timeline. # See the docstring above for details. state_ids: StateMap[str] - + # We need to know whether the state we fetch may be partial, so check + # whether the room is partial stated *before* fetching it. + is_partial_state_room = await self.store.is_partial_state_room(room_id) if full_state: if batch: state_at_timeline_end = ( @@ -1119,7 +1133,7 @@ class SyncHandler: # If we only have partial state for the room, `state_ids` may be missing the # memberships we wanted. We attempt to find some by digging through the auth # events of timeline events. - if lazy_load_members and await self.store.is_partial_state_room(room_id): + if lazy_load_members and is_partial_state_room: assert members_to_fetch is not None assert first_event_by_sender_map is not None |