anchor.diff:    // and END.
     int _selectRow = -1;
   
  -  StreamSubscription _subscription;
  -
  -  bool get active => _subscription != null;
  +  StreamSubscription _keyEventSubscription;
  +
  +  bool get active => _keyEventSubscription != null;
   
     Function _finishCallback;
   
  
positive.code:       selectedScriptRef = _scriptsView._highlightRef;
      }
  
      if (_subscription != null) {
        // No more event routing until user has clicked again the the textfield.
        _subscription.cancel();
        _subscription = null;
      }
  
      // Remember the whole set of ScriptRefs
  
negative.code:     _startMatching(revertScriptRef, true);
  
      // Start handling user's keystrokes to show matching list of files.
      _keyEventSubscription ??=
          _textfield.onKeyDown.listen((html.KeyboardEvent e) {
        switch (e.keyCode) {
          case DOM_VK_RETURN:
            reset();
  