Bug Tracker

Ticket #7809 (closed bug: duplicate)

Opened 5 years ago

Last modified 5 years ago

jQuery Clone Bug 1.4.2+

Reported by: ambar Owned by:
Priority: undecided Milestone: 1.6
Component: unfiled Version: 1.4.4
Keywords: Cc:
Blocking: Blocked by:



Array.prototype.xyzz = function (arg) {
Array.prototype.xyzzz = function (arg) {

$(function() {
	$('button').click(function () {
		$('div.demo').clone(true).appendTo( 'body' );
	$('div.demo').click(function () {

click the new div will trigger this bug.

bug src

// event.js, jQuery.event.add:
// before jQuery 1.4.1
handlers = events[ type ] = {};
// jQuery 1.4.2+
handlers = events[ type ] = [];

// manipulation.js, jQuery.clone : , cloneCopyEvent():
for ( var type in events ) {
	for ( var handler in events[ type ] ) {
		jQuery.event.add( this, type, events[ type ][ handler ], events[ type ][ handler ].data );


there is no hasOwnProperty() check in for...in loop, use each() is better.

var self = this;
for ( var type in events ) {
	jQuery.each(events[ type ],function(idx,evt) {
		jQuery.event.add( self, type, evt.handler, evt.data );

Change History

comment:2 Changed 5 years ago by Section_Ei8ht

Came here to submit this exact bug. Could be solved using either each() or a for statement rather than a for-in statement as the nested loop.

comment:3 Changed 5 years ago by rwaldron

  • Status changed from new to closed
  • Resolution set to invalid

If you augment or extend native/host objects, such as Array.prototype, your code will exhibit unexpected behaviour

comment:4 Changed 5 years ago by Section_Ei8ht

I apologize if this comment comes across as harsh, but I disagree with the reason for invalidating this ticket. jQuery has a no conflict mode to allow it to be used together with libraries like Prototype, but Prototype modifies the prototypes of several native objects (Array, in this case), which makes this a bug in the compatibility of jQuery with other libraries. You shouldn't say that the fix for this problem is to simply not do it when your documentation says that you can.

It's a one line change, and I respectfully feel that the reason supplied for closing this ticket seems to me to be against the entire mantra of jQuery itself (everything being contained in the jQuery namespace), and a cop-out answer.

I've submitted a pull request to the jQuery github repository that fixes this ticket:  https://github.com/jquery/jquery/pull/138

comment:5 Changed 5 years ago by dmethvin

  • Status changed from closed to reopened
  • Resolution invalid deleted

comment:6 Changed 5 years ago by dmethvin

  • Status changed from reopened to closed
  • Resolution set to duplicate

comment:7 Changed 5 years ago by dmethvin

Duplicate of #6355.

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