User Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; Zune 4.7; InfoPath.3) Steps to reproduce: Firefox 12 does not read the setting : defaultPref("browser.startup.homepage"...) in the file autoconfig.cfg. It worked with Firefox 10. Actual results: In Firefox12, The setting defaultPref("browser.startup.homepage", "<A href="http://www.yahoo.com">http://www.google.com</A>"); in an autoconfig doesn't work. It worked before in version 10.0 The setting Pref("browser.startup.homepage",) is working properly. Expected results: With Firefox 10, Mozilla read the setting defaultPref properly (ex: google.com). user can change this browser startup homepage if necessary
according to bug449456#c7 this doesn't work as defaultpref.
I just tested on the ESR (Firefox 10) and verified that defaultPref does not work (and it shouldn't). The preference browser.startup.homepage is a complex preference when used as a default preference. So it cannnot be specified as in the config file directly in the normal way. There is a work around for this. You can set the preference like this: defaultPref("browser.startup.homepage", "data:text/plain,browser.startup.homepage=http://www.yahoo.com/"); And it should work (it did in my testing on Firefox 10). I also verified it works in Firefox 12.