Ugh. My workaround selector got gobbled. It's the boolean attribute set to an empty string, if that makes sense. It's clear in the test page, anyhow.

The spec definitely does not say that boolean attributes are not allowed to have a value. autofocus="autofocus" is 100% valid; this always has been, and always will be, the case for boolean attributes.

You can still end up running into this problem with valid code, but there is a clean workaround.

Scott, you're right--I misread that part of the spec.

Nonetheless, the real issue here is not with attributes, but with selectors. Considering <input type=text required> as legit markup, and the selector [required] {} as a legit selector in both the CSS2.1 and CSS3 specs--I see no reason that jQuery should force authors to use <input type=text required=required>, as a workaround so they can use [required=required] {}.

Are there any other instances you can point me to where jQuery forces users to use a particular style of (X)HTML?

I wanted this too so I tried fixing the attribute selector in sizzle.js, in a big block of code that looks like this:

return result == null ?

type === "!=" :

type === "=" ?

value === check :

type === "*=" ?

value.indexOf(check) >= 0 :

type === "~=" ?

(" " + value + " ").indexOf(check) >= 0 :

!check ?

value && result !== false :

type === "!=" ?

value !== check :

type === "^=" ?

value.indexOf(check) === 0 :

type === "$=" ?

value.substr(value.length - check.length) === check :

type === "|=" ?

value === check || value.substr(0, check.length + 1) === check + "-" :

false;

However, it turns out that while you can make it work for unknown-to-IE attributes to <time pubdate>, <video autoplay>, etc, you will instead break simple selectors like [title]. Reading: http://tobielangel.com/2007/1/11/attribute-nightmare-in-ie/ and http://andrewdupont.net/2007/01/10/code-hasattribute-for-ie/ (the comments, the body of the post doesn't have any code for some reason).

Unless a reliable way to distinguish between missing and empty attributes in IE can be found, this just can't be fixed.

Closing since there is a valid workaround. :'( If anyone cares to reopen with a patch, feel free.

Reopening...

Testcase from deadlyicon http://jsfiddle.net/B974R/

Perhaps this should be a docs issue? Would be ideal for a real fix though..

Attr nodes (from getAttributeNode) have a property specified that allows us to query whether or not an attribute has actually been specified, as opposed to being empty.

#7874 is a duplicate of this ticket.

Just noticed that the jsfiddle testcase in Paul's comment seems like an entirely different issue. href is a normal attribute, not a boolean one. However, it could be that both issues are symptoms of the same problem in Sizzle.

Also, here's 80 qunit tests that I should have linked to last year, should they come in handy:

http://miketaylr.com/test/qunit/html5booleans_shallow.html

This is getting moved to 1.6 for when the $.attr happens.

http://jsfiddle.net/kBK8v/4/

potentially the same problem

var d = $(document),

global = $('[required]').length,

first = $('[required]').first().is('[required]');

in IE, global query returns the correct count, but first returns false, rather then true for the single IS call.

As far as I can tell, the bug is not related to IE6/7 only. Actually, this takes place in ANY browser with no native querySelector() support (for example Firefox 3.0). So, apparently this is the bug of pure-script implementation of selectors engine of jQuery/Sizzle.

The workaround is acceptable only as ''temporary'' solution in a particular cases.

#8758 is a duplicate of this ticket.

Nominating ticket for 1.7 discussion.

+1,

+1, Sounds like a bug, should be fixed

+1, in principle, I'd go for this, but what would be the performance cost across all supported browsers?

+1, I'd like to see this fixed, and it will only come up with more frequency until we do

+1, I imagine unifying jQuery.attr and Sizzle attributes will fix this and perhaps reduce the codebase.

+1

+1

+1, Good bug to fix.

+1, Yeah, timmywil and I will work on getting this fixed.

+1, probably needs a configurable whitelist

+1

+1, and another +1 for making shim-building easier

+0

#9637 is a duplicate of this ticket.

#7234 is a duplicate of this ticket.

#6004 is a duplicate of this ticket.

#7770 is a duplicate of this ticket.

#7555 is a duplicate of this ticket.

I have problems related to this with this HTML code in IE7:

<span datetime="'2011-08-19T00:00:00-07:00'">Some Text Here!</span>

$("span[datetime]") returns an empty jQuery object.

Override Sizzle attribute retrieval with jQuery.attr. Fixes #5637, #7128, #9261, #9570, #10178.

Bug fixed on the side: $(window).is('a') was throwing an exception. Fixes #10178.

Changeset: 92405d4f5ffe9ec1f26f280303783014948438c5