id,summary,reporter,owner,description,type,status,priority,milestone,component,version,severity,resolution,keywords,cc
18022,Author dropdown on post.php hangs in IE if number of usernames is large,dbvista,,"When I visit wp-admin/posts.php to post a new article in Internet Explorer 8, and click the '''Author''' dropdown to try to change the author, and the dropdown contains ''many usernames'' (say, 1000), the dropdown does not open and the entire web page hangs. (This does not happen in Firefox.) After several seconds, IE displays this error dialog:

''Stop running this script?
A script on this page is causing Internet Explorer to run slowly. If it continues to run, your computer may become unresponsive.''

Dismissing the dialog makes the web page come back to life; however, the dropdown does not open.

If you reduce the number of usernames in the dropdown, the problem goes away. This suggests that WordPress JavaScript is running very slowly, proportional to the number of usernames.

You may be tempted to think this is a Microsoft or IE problem, but here some evidence that it's a WordPress problem:

1. I created a plain HTML page with a 5000-item dropdown, and the same IE browser displayed it immediately without any delay. This suggests the problem is unique to WordPress. 

2. The problem does not occur in Firefox (3.6.18). This suggests that WordPress has an IE-specific performance problem in some JavaScript code.

3. Possible clue: If I remove the following line from wp-admin/admin-header.php, the problem disappears. This suggests WordPress is adding some kind of JavaScript processing to this dropdown that is slowing it down.

{{{
ajaxurl = '<?php echo admin_url('admin-ajax.php'); ?>',
}}}

Deactivating all plugins and changing theme to Twenty Ten does not affect the problem.

I posted about this in the forums first:
http://wordpress.org/support/topic/author-dropdown-on-postphp-displays-ie-error-stop-running-this-script

Other people have reported this problem in version 3.2:
http://wordpress.org/support/topic/cannot-edit-change-author-when-editing-blog-posts-with-word-press-324

I am happy to participate in solving this by running tests you come up with.",defect (bug),closed,normal,,Administration,3.1,normal,wontfix,,