In all versions of jQuery, including the latest (1.6.2), in both IE7 and IE8, a has-attribute selector will return false positives for all TH tags when testing for the colspan attribute.

Tested on Windows 7.

I submit this hoping something can be done about this, despite its roots likely being in the [flawed] browsers themselves.

Example HTML:

<table id="one"><tr><th>fred</th></tr></table>
<table id="two"><tr><td>fred</td></tr></table>

Example JS:

alert($('#one').find('th[colspan!=""]').length); //Returns 1
alert($('#one').find('th[colspan]').length); //Returns 1

alert($('#two').find('td[colspan!=""]').length); //Returns 1
alert($('#two').find('td[colspan]').length); //Returns 1

$('#one').find('th').each(function() {
    alert('colspan:' + $(this).attr('colspan')); //Returns 1 in IE7,8 and "undefined" otherwise
});

http://jsfiddle.net/GHXBH/6/

Clearly, given this code sample, this attribute should return 0 in IE7 and 8, as it does with IE9, FireFox, and Chrome.

In the last loop, you will see that I output the attribute of the colspan for the TH in the table. In IE7 and 8, a "1" is returned, meaning a colspan of "1". In IE9, and all non-IE browsers, "undefined" is the result as expected.

Thank you, and my apologies if this has been reported (I, however, could not find a duplicate).