$.extend does not copy own property of form element

[telensky]

If I assign property 'form_idx' to the form element and then use $.extend(), the property is not copied! See testcase available at ​http://artax.karlin.mff.cuni.cz/~ttel5535/WEB_development/BUGS/091215-jquery_extend/jq_err_simple.html

I would expect the secold alert to say that form_idx is 123.

The snip of the code:

var fe = $('form').get(0);

fe.form_idx = 123;

alert('this.form_idx == ' + fe.form_idx + ', OwnProperty == ' + fe.hasOwnProperty('form_idx'));

b = $.extend({}, fe);

alert('b.form_idx == ' + b.form_idx); how comes that this is undefined!!!

[dmethvin]

$.extend() is not meant to copy or extend DOM elements. If you want to make a copy of a DOM element, use $(el).clone() and not $.extend(). IE in particular doesn't treat a DOM element the same as a Javascript object.