diff options
Diffstat (limited to 'synapse/handlers/_base.py')
| -rw-r--r-- | synapse/handlers/_base.py | 25 |
1 files changed, 22 insertions, 3 deletions
diff --git a/synapse/handlers/_base.py b/synapse/handlers/_base.py index 2333fc0c09..c6a74b0e3d 100644 --- a/synapse/handlers/_base.py +++ b/synapse/handlers/_base.py @@ -199,8 +199,7 @@ class BaseHandler(object): # events in the room, because we don't know enough about the graph # fragment we received to treat it like a graph, so the above returned # no relevant events. It may have returned some events (if we have - # joined and left the room), but not useful ones, like the invite. So we - # forcibly set our context to the invite we received over federation. + # joined and left the room), but not useful ones, like the invite. if ( not self.is_host_in_room(context.current_state) and builder.type == EventTypes.Member @@ -208,7 +207,27 @@ class BaseHandler(object): prev_member_event = yield self.store.get_room_member( builder.sender, builder.room_id ) - if prev_member_event: + + # The prev_member_event may already be in context.current_state, + # despite us not being present in the room; in particular, if + # inviting user, and all other local users, have already left. + # + # In that case, we have all the information we need, and we don't + # want to drop "context" - not least because we may need to handle + # the invite locally, which will require us to have the whole + # context (not just prev_member_event) to auth it. + # + context_event_ids = ( + e.event_id for e in context.current_state.values() + ) + + if ( + prev_member_event and + prev_member_event.event_id not in context_event_ids + ): + # The prev_member_event is missing from context, so it must + # have arrived over federation and is an outlier. We forcibly + # set our context to the invite we received over federation builder.prev_events = ( prev_member_event.event_id, prev_member_event.prev_events |