diff --git a/synapse/federation/federation_client.py b/synapse/federation/federation_client.py
index 8493ffc2e5..0ac85a3be7 100644
--- a/synapse/federation/federation_client.py
+++ b/synapse/federation/federation_client.py
@@ -19,6 +19,7 @@ import itertools
import logging
from typing import (
TYPE_CHECKING,
+ AbstractSet,
Awaitable,
Callable,
Collection,
@@ -110,8 +111,9 @@ class SendJoinResult:
# True if 'state' elides non-critical membership events
partial_state: bool
- # if 'partial_state' is set, a list of the servers in the room (otherwise empty)
- servers_in_room: List[str]
+ # If 'partial_state' is set, a set of the servers in the room (otherwise empty).
+ # Always contains the server we joined off.
+ servers_in_room: AbstractSet[str]
class FederationClient(FederationBase):
@@ -1152,15 +1154,24 @@ class FederationClient(FederationBase):
% (auth_chain_create_events,)
)
- if response.members_omitted and not response.servers_in_room:
- raise InvalidResponseError(
- "members_omitted was set, but no servers were listed in the room"
- )
+ servers_in_room = None
+ if response.servers_in_room is not None:
+ servers_in_room = set(response.servers_in_room)
- if response.members_omitted and not partial_state:
- raise InvalidResponseError(
- "members_omitted was set, but we asked for full state"
- )
+ if response.members_omitted:
+ if not servers_in_room:
+ raise InvalidResponseError(
+ "members_omitted was set, but no servers were listed in the room"
+ )
+
+ if not partial_state:
+ raise InvalidResponseError(
+ "members_omitted was set, but we asked for full state"
+ )
+
+ # `servers_in_room` is supposed to be a complete list.
+ # Fix things up in case the remote homeserver is badly behaved.
+ servers_in_room.add(destination)
return SendJoinResult(
event=event,
@@ -1168,7 +1179,7 @@ class FederationClient(FederationBase):
auth_chain=signed_auth,
origin=destination,
partial_state=response.members_omitted,
- servers_in_room=response.servers_in_room or [],
+ servers_in_room=servers_in_room or frozenset(),
)
# MSC3083 defines additional error codes for room joins.
|
