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#3680 closed bug (fixed)

Opened December 03, 2008 04:44AM UTC

Closed March 08, 2010 09:49PM UTC

Leading/trailing space not treated consistently in className

Reported by: rmurphey Owned by:
Priority: minor Milestone: 1.4
Component: core Version: 1.3.2
Keywords: Cc:
Blocked by: Blocking:

[this probably needs a better description]

I've set up a demo page that shows this bug in detail at:

I am populating a page with HTML contained in a JSON object sent by the server. Once the page is populated, I attempt to run the following jQuery:


There are 54 li's that should match; Firefox 3 finds them, but other major browsers do not. I suspect the issue occurs when a class attribute contains some escape characters in the JSON, e.g.:

<li class=\\"toggle\\r\\n\\t\\t\\t\\t\\t\\t\\t\\t\\t\\t\\">

The following will result in alerts as appropriate, at least in Safari:

$('li).each(function() {

if (this.className.match('toggle')) { alert('match'); }


But this will not:

$('li').each(function() {

if (this.className == 'toggle') { alert('match'); }


Attachments (2)
  • test-3680.html (0.6 KB) - added by dmethvin May 06, 2009 03:35AM UTC.

    Works for FF and IE8.

  • test_class_selector.html (0.5 KB) - added by batiste November 16, 2009 09:15AM UTC.

    A test that try to reproduce the bug 3680

Change History (7)

Changed December 03, 2008 01:41PM UTC by flesler comment:1

component: selectorcore
need: ReviewTest Case

That's odd, IE's regex engine does match \\r, \\n and \\t when using /\\s/.

Can you provide a test case ? an html file that reproduces the problem.

Try not to use ajax, add the json within a js file and include it.

Changed December 03, 2008 03:57PM UTC by rmurphey comment:2

I've updated the test case at

it wasn't using AJAX before, it was just populating the div with the json when the a#load was clicked.

Changed December 03, 2008 04:32PM UTC by rmurphey comment:3

Per the test case page I posted, this is a problem in:

  • Safari 3.2
  • IE6
  • IE7

Changed May 06, 2009 03:33AM UTC by dmethvin comment:4

With a newline in the string, you are creating HTML like:

<li class=\\"toggle


"User agents may ignore leading and trailing white space in CDATA attribute values (e.g., " myval " may be interpreted as "myval"). Authors should not declare attribute values with leading or trailing white space."

I've attached a test case that shows that even with bare HTML/DOM, Firefox trims the trailing newlines/spaces but IE does not. Both are valid. The test correctly shows that 2 elements are selected in both IE and Firefox.

Whatever the problem is here, it seems that it's very dubious to depend on the behavior of trailing whitespace in a class name.

Changed November 14, 2009 03:33PM UTC by dmethvin comment:5

summary: Elements that match selector are found in some browsers, not found in othersLeading/trailing space not treated consistently in className

Changed November 16, 2009 09:18AM UTC by batiste comment:6

I try to reproduce this bug but without success. Seems fixed to me.

Changed March 08, 2010 09:49PM UTC by john comment:7

milestone: 1.31.4
resolution: → fixed
status: newclosed

This has since been fixed in jQuery 1.4.