Merge branch 'main' into neilalexander/localservernames

syncapi/routing/memberships.go

@@ -109,6 +109,12 @@ func GetMemberships(
 	}
 
 	if joinedOnly {
+		if !queryRes.IsInRoom {
+			return util.JSONResponse{
+				Code: http.StatusForbidden,
+				JSON: jsonerror.Forbidden("You aren't a member of the room and weren't previously a member of the room."),
+			}
+		}
 		var res getJoinedMembersResponse
 		res.Joined = make(map[string]joinedMember)
 		for _, ev := range result {

syncapi/streams/stream_pdu.go

@@ -227,14 +227,10 @@ func (p *PDUStreamProvider) addRoomDeltaToResponse(
 	stateFilter *gomatrixserverlib.StateFilter,
 	req *types.SyncRequest,
 ) (types.StreamPosition, error) {
-	if delta.MembershipPos > 0 && delta.Membership == gomatrixserverlib.Leave {
-		// make sure we don't leak recent events after the leave event.
-		// TODO: History visibility makes this somewhat complex to handle correctly. For example:
-		// TODO: This doesn't work for join -> leave in a single /sync request (see events prior to join).
-		// TODO: This will fail on join -> leave -> sensitive msg -> join -> leave
-		//       in a single /sync request
-		// This is all "okay" assuming history_visibility == "shared" which it is by default.
-		r.To = delta.MembershipPos
+
+	originalLimit := eventFilter.Limit
+	if r.Backwards {
+		eventFilter.Limit = int(r.From - r.To)
 	}
 	recentStreamEvents, limited, err := snapshot.RecentEvents(
 		ctx, delta.RoomID, r,
@@ -303,6 +299,12 @@ func (p *PDUStreamProvider) addRoomDeltaToResponse(
 		logrus.WithError(err).Error("unable to apply history visibility filter")
 	}
 
+	if r.Backwards && len(events) > originalLimit {
+		// We're going backwards and the events are ordered chronologically, so take the last `limit` events
+		events = events[len(events)-originalLimit:]
+		limited = true
+	}
+
 	if len(delta.StateEvents) > 0 {
 		updateLatestPosition(delta.StateEvents[len(delta.StateEvents)-1].EventID())
 	}

sytest-whitelist

@@ -757,3 +757,4 @@ Can get rooms/{roomId}/messages for a departed room (SPEC-216)
 Local device key changes appear in /keys/changes
 Can get rooms/{roomId}/members at a given point
 Can filter rooms/{roomId}/members
+Current state appears in timeline in private history with many messages after