579844 - Firefox does not forget a proxy setting when transitioning from "Use system proxy settings" to "No Proxy"

Status: RESOLVED WORKSFORME

(Firefox :: Settings UI, defect)

Description

[Maurice David Wörnhard]

User-Agent:       Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2.6) Gecko/20100625 Firefox/3.6.6
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.6) Gecko/20100625 Firefox/3.6.6

Firefox does not stop using a proxy it picked up from Windows ("Use system proxy settings", set on Windows via GPO or a local agent like Microsoft Threat Management Gateway 2010) even though the user selects "No Proxy" under Tools -> Options -> Advanced -> Network -> Settings.

Reproducible: Always

Steps to Reproduce:
1. Per default, Firefox has the setting "Use system proxy settings" in Tools/Options, register "Advanced", subtab "Network", button "Settings...". Now if Windows get's configured with a proxy (either by GPO, or some local agent like TMG 2010 Client), Firefox also starts using this proxy
2. Change the proxy setting from "Use system proxy settings" to "No proxy" - but Firefox continues to use the proxy. Verify by visiting a site like http://www.heise.de/ip (showing your IP and if you are using a proxy). - A program restart does not help either.
Actual Results:  
Firefox continues using the proxy it picked up from Windows.

Expected Results:  
Firefox should stop using the proxy.

Workaround:

1. Change the proxy setting from "No proxy" to "Auto-detect proxy settings for this network". Now Firefox looses the proxy information.
2. Change the proxy setting back to "No proxy" and now it works.

I tested both with TMG 2010 Agent and with Windows/IE proxy settings deployed via GPO.

Comment 1

[Patrick McManus [:mcmanus]]

tested with 2012/sep/3 nightly