Merge pull request matrix-org#3738 from matrix-org/t3chguy/null-guard-useIsEncrypted

Fix UserInfo exploding without a room being passed to it

Author: t3chguy

src/components/views/right_panel/UserInfo.js

@@ -109,14 +109,14 @@ function openDMForUser(matrixClient, userId) {
 }
 
 function useIsEncrypted(cli, room) {
- const [isEncrypted, setIsEncrypted] = useState(cli.isRoomEncrypted(room.roomId));
+ const [isEncrypted, setIsEncrypted] = useState(room ? cli.isRoomEncrypted(room.roomId) : undefined);
 
  const update = useCallback((event) => {
  if (event.getType() === "m.room.encryption") {
  setIsEncrypted(cli.isRoomEncrypted(room.roomId));
  }
  }, [cli, room]);
- useEventEmitter(room.currentState, "RoomState.events", update);
+ useEventEmitter(room ? room.currentState : undefined, "RoomState.events", update);
  return isEncrypted;
 }
 

src/hooks/useEventEmitter.js

@@ -28,6 +28,9 @@ export const useEventEmitter = (emitter, eventName, handler) => {
 
  useEffect(
  () => {
+ // allow disabling this hook by passing a falsy emitter
+ if (!emitter) return;
+
  // Create event listener that calls handler function stored in ref
  const eventListener = event => savedHandler.current(event);