weakBind bug - only half gets called

[comanche]

When listeners are added with weakBind, only half of them gets called. The problem seems to be with the following code starting on line 173 to 189:

for(var j = 0; j < listeners.length; j += 1) {
  switch(arguments.length) {
    case 1:
      _cancelBubble = listeners[j].call(this);
      break;
    case 2:
      _cancelBubble = listeners[j].call(this, arguments[1]);
      break;
    case 3:
      _cancelBubble = listeners[j].call(this, arguments[1], arguments[2]);
      break;
    default:
      var args = arguments.slice ? arguments.slice(1) : Array.prototype.slice.call(arguments, 1);
      _cancelBubble = listeners[j].apply(this, args);
  }
  if(_cancelBubble === false) { this.cancelBubble = false; }
}

As listener handlers are called, they are removed. listeners.length decreases at the same time as the counter j is incremented. This causes only half of the listeners to get called.

This issue does not affect listeners added via bind. However, if the listener removes itself with unbind when called, the same issue arises. While this loop is running, if anything affects the size of listeners, there will be issue.

[RobertWHurst]

Thanks for pointing that out. I'll get a fix in.

[comanche]

Possibly the quickest fix is to check if the listener was removed and offset the counter.

for(var j = 0; j < listeners.length; j += 1) {
  var listener = listeners[j];
  switch(arguments.length) {
    case 1:
      _cancelBubble = listener.call(this);
      break;
    case 2:
      _cancelBubble = listener.call(this, arguments[1]);
      break;
    case 3:
      _cancelBubble = listener.call(this, arguments[1], arguments[2]);
      break;
    default:
      var args = arguments.slice ? arguments.slice(1) : Array.prototype.slice.call(arguments, 1);
      _cancelBubble = listener.apply(this, args);
  }
  if(_cancelBubble === false) { this.cancelBubble = false; }
  // If the listener was removed from the list of listeners after call,
  // offset the counter to prevent increment.
  if (listener !== listeners[j]) { j--; }
}

[RobertWHurst]

This should now be fixed