User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:2.0b13pre) Gecko/20110302 Firefox/4.0b13pre Build Identifier: When I use a NTML proxy with Authentication, all asynchronous HTTP requests done by tbpl failed with error 407 Proxy Authentication Required Reproducible: Always Steps to Reproduce: 1. Setup a proxy with authentication 2. Go to http://tbpl.mozilla.org/ Actual Results: No pushes are loaded and the message "Loading 34%" is displayed forever Sample headers of a failed request (obtained using Firebug) : GET http://tinderbox.mozilla.org/Firefox/status.html HTTP/1.1 Host: tinderbox.mozilla.org User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:2.0b13pre) Gecko/20110302 Firefox/4.0b13pre Accept: text/plain, */* Accept-Language: fr,fr-fr;q=0.8,en-us;q=0.5,en;q=0.3 Accept-Encoding: gzip, deflate Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7 Keep-Alive: 115 Proxy-Connection: keep-alive Referer: http://tbpl.mozilla.org/ Origin: http://tbpl.mozilla.org HTTP/1.1 407 Proxy Authentication Required Mime-Version: 1.0 Date: Thu, 03 Mar 2011 11:05:39 CET Content-Type: text/html Proxy-Authenticate: NTLM Basic realm="IronPort Web Security Appliance" Connection: close Content-Length: 2160

The fixed for bug 638218 do nothing for this bug. I don't think they are the same.

Okay, it was just a guess :) Is this a regression? Can you reproduce it with other browser, too?

I can reproduce the bug with Firefox 3.6.14, if it is a regression, it's an old one.

What happens if you go to http://tinderbox.mozilla.org/Firefox/status.html directly? Is that also blocked?

It works without problem. For some reason, it seems that the ajax call done by the main page don't use the already saved proxy authentication. It's strange, because other site with ajax request (gmail for example) don't have this problem.

OK, I have no idea what to do here.

I've thinked about. The difference between this Ajax calls and others is that on tbpl thé request is cross domain. In that case Firefox do not send cookies neither proxy authentication. I understand the security implication for cookies or site authentication, but it's bad for proxies.