send_join response: get create event from state, not auth_chain (…

…#12005) msc3706 proposes changing the `/send_join` response: > Any events returned within `state` can be omitted from `auth_chain`. Currently, we rely on `m.room.create` being returned in `auth_chain`, but since the `m.room.create` event must necessarily be part of the state, the above change will break this. In short, let's look for `m.room.create` in `state` rather than `auth_chain`.
matrix-org · Feb 17, 2022 · 696acd3 · 696acd3
1 parent 4077177
commit 696acd3
Show file tree

Hide file tree

Showing 2 changed files with 2 additions and 1 deletion.
diff --git a/changelog.d/12005.misc b/changelog.d/12005.misc
@@ -0,0 +1 @@
+Preparation for faster-room-join work: when parsing the `send_join` response, get the `m.room.create` event from `state`, not `auth_chain`.
diff --git a/synapse/handlers/federation_event.py b/synapse/handlers/federation_event.py
@@ -420,7 +420,7 @@ async def process_remote_join(
             SynapseError if the response is in some way invalid.
         """
         create_event = None
-        for e in auth_events:
+        for e in state:
             if (e.type, e.state_key) == (EventTypes.Create, ""):
                 create_event = e
                 break
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		Preparation for faster-room-join work: when parsing the `send_join` response, get the `m.room.create` event from `state`, not `auth_chain`.