Pass room to getRoomTombstone to avoid racing with setState

src/components/structures/RoomView.tsx

@@ -1028,13 +1028,13 @@ export class RoomView extends React.Component<IRoomProps, IRoomState> {
         this.checkWidgets(room);
 
         this.setState({
-            tombstone: this.getRoomTombstone(),
+            tombstone: this.getRoomTombstone(room),
             liveTimeline: room.getLiveTimeline(),
         });
     };
 
-    private getRoomTombstone() {
-        return this.state.room?.currentState.getStateEvents(EventType.RoomTombstone, "");
+    private getRoomTombstone(room = this.state.room) {
+        return room?.currentState.getStateEvents(EventType.RoomTombstone, "");
     }
 
     private async calculateRecommendedVersion(room: Room) {