User Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:22.214.171.124) Gecko/20110710 Gentoo Firefox/3.6.17 Build ID: 20110710150528 Steps to reproduce: I set up WPAD on my network. I verified that it works with Firefox if I configure Firefox to "Autodetect proxy settings for this network". Now configure Gnome network proxy to "Automatic proxy configuration, but leave the "Autoconfoguration URL" empty. I verified that WPAD works with Epiphany/WebKit, and libproxy's 'proxy' command line tool. Now configure Firefox to "Use system proxy settings". Actual results: Firefox doesn't use WPAD. Expected results: Firefox should use WPAD.
Note that if I manually point the Gnome proxy settings "Autoconfiguration URL" to a PAC file, Firefox does pick it up correctly. I suppose Firefox simply doesn't realize that if the gconf key /system/proxy/autoconfig_url is empty, it should use WPAD.
Why should Firefox use WPAD if you do not enter a URL in the autoconfig url file? Just enter "http://wpad/wpad.dat" (the WPAD URL) and it works. Seems pretty straight-forward to me as wpad.dat is essentially a PAC file as well.