Don't send `adds_state_events` in roomserver output events anymore (#2258)

* Don't send `adds_state_events` in roomserver output events anymore

* Set `omitempty` on some output fields that aren't always set

* Add `AddsState` helper function

* No-op if no added state event IDs

* Revert "No-op if no added state event IDs"

This reverts commit 71a0ef3df10e0d94234d916246c30b0a4e82b26e.

* Revert "Add `AddsState` helper function"

This reverts commit c9fbe45475eb12ae44d2a8da7c0fc3a002ad9819.

1 files changed, 22 insertions, 1 deletions

diff --git a/federationapi/consumers/roomserver.go b/federationapi/consumers/roomserver.go
index 173dcff0..989f7cf4 100644
--- a/federationapi/consumers/roomserver.go
+++ b/federationapi/consumers/roomserver.go
@@ -146,7 +146,28 @@ func (s *OutputRoomEventConsumer) processInboundPeek(orp api.OutputNewInboundPee
 // processMessage updates the list of currently joined hosts in the room
 // and then sends the event to the hosts that were joined before the event.
 func (s *OutputRoomEventConsumer) processMessage(ore api.OutputNewRoomEvent) error {
-	addsJoinedHosts, err := joinedHostsFromEvents(gomatrixserverlib.UnwrapEventHeaders(ore.AddsState()))
+	eventsRes := &api.QueryEventsByIDResponse{}
+	if len(ore.AddsStateEventIDs) > 0 {
+		eventsReq := &api.QueryEventsByIDRequest{
+			EventIDs: ore.AddsStateEventIDs,
+		}
+		if err := s.rsAPI.QueryEventsByID(s.ctx, eventsReq, eventsRes); err != nil {
+			return fmt.Errorf("s.rsAPI.QueryEventsByID: %w", err)
+		}
+
+		found := false
+		for _, event := range eventsRes.Events {
+			if event.EventID() == ore.Event.EventID() {
+				found = true
+				break
+			}
+		}
+		if !found {
+			eventsRes.Events = append(eventsRes.Events, ore.Event)
+		}
+	}
+
+	addsJoinedHosts, err := joinedHostsFromEvents(gomatrixserverlib.UnwrapEventHeaders(eventsRes.Events))
 	if err != nil {
 		return err
 	}