From fc2c431e29fa15d928b0f425a1cf136f19d0e76c Mon Sep 17 00:00:00 2001
From: Neil Alexander <neilalexander@users.noreply.github.com>
Date: Tue, 1 Sep 2020 14:06:52 +0100
Subject: [PATCH] Don't accumulate state IDs to overwrite

---
 roomserver/api/wrapper.go           | 24 ++++++++----------------
 roomserver/internal/input_events.go |  6 +++---
 2 files changed, 11 insertions(+), 19 deletions(-)

diff --git a/roomserver/api/wrapper.go b/roomserver/api/wrapper.go
index 9529109e9..b1af1910d 100644
--- a/roomserver/api/wrapper.go
+++ b/roomserver/api/wrapper.go
@@ -48,37 +48,29 @@ func SendEventWithState(
 	ctx context.Context, rsAPI RoomserverInternalAPI, state *gomatrixserverlib.RespState,
 	event gomatrixserverlib.HeaderedEvent, haveEventIDs map[string]bool, stateKind Kind,
 ) error {
-	outliers, err := state.Events()
+	events, err := state.Events()
 	if err != nil {
 		return err
 	}
 
 	var ires []InputRoomEvent
-	var stateEventIDs []string
 
-	for _, outlier := range outliers {
-		if haveEventIDs[outlier.EventID()] {
+	for _, ev := range events {
+		if haveEventIDs[ev.EventID()] {
 			continue
 		}
 		in := InputRoomEvent{
 			Kind:         stateKind,
-			Event:        outlier.Headered(event.RoomVersion),
-			AuthEventIDs: outlier.AuthEventIDs(),
-		}
-		if stateKind == KindNew {
-			in.HasState = true
-			in.StateEventIDs = stateEventIDs
+			Event:        ev.Headered(event.RoomVersion),
+			AuthEventIDs: ev.AuthEventIDs(),
 		}
 		ires = append(ires, in)
-		stateEventIDs = append(stateEventIDs, outlier.EventID())
 	}
 
 	ires = append(ires, InputRoomEvent{
-		Kind:          KindNew,
-		Event:         event,
-		AuthEventIDs:  event.AuthEventIDs(),
-		HasState:      true,
-		StateEventIDs: stateEventIDs,
+		Kind:         KindNew,
+		Event:        event,
+		AuthEventIDs: event.AuthEventIDs(),
 	})
 
 	_, err = SendInputRoomEvents(ctx, rsAPI, ires)
diff --git a/roomserver/internal/input_events.go b/roomserver/internal/input_events.go
index a63082990..3c2905442 100644
--- a/roomserver/internal/input_events.go
+++ b/roomserver/internal/input_events.go
@@ -158,18 +158,18 @@ func (r *RoomserverInternalAPI) calculateAndSetState(
 		// Check that those state events are in the database and store the state.
 		var entries []types.StateEntry
 		if entries, err = r.DB.StateEntriesForEventIDs(ctx, input.StateEventIDs); err != nil {
-			return err
+			return fmt.Errorf("r.DB.StateEntriesForEventIDs: %w", err)
 		}
 
 		if stateAtEvent.BeforeStateSnapshotNID, err = r.DB.AddState(ctx, roomNID, nil, entries); err != nil {
-			return err
+			return fmt.Errorf("r.DB.AddState: %w", err)
 		}
 	} else {
 		stateAtEvent.Overwrite = false
 
 		// We haven't been told what the state at the event is so we need to calculate it from the prev_events
 		if stateAtEvent.BeforeStateSnapshotNID, err = roomState.CalculateAndStoreStateBeforeEvent(ctx, event, roomNID); err != nil {
-			return err
+			return fmt.Errorf("roomState.CalculateAndStoreStateBeforeEvent: %w", err)
 		}
 	}
 	return r.DB.SetState(ctx, stateAtEvent.EventNID, stateAtEvent.BeforeStateSnapshotNID)