if in this user.js I specify a preference from the extension's defaults/preferences/prefs.js directory, then the retrieved preference value is always the value from defaults/preferences/prefs.js and not the value from user.js.

I've seen a similar report to this against Thunderbird I believe, unfortunately I can't find it at the moment.

Dave, is this a known issue for Firefox?

It's not something I've come across before, this should probably be moved to the preferences component.

It's probably just a problem with us loading extension defaults later than user.js, this may even be a regression since Firefox 4 as we meddled with the pref loading there.

We need to be careful, though, in relegating this to Core. While I would prefer to fix it there, the Mozmill issue needs to be addressed in any case.

Feel free to move it back and file a new bug in core or vice-versa then.

Jeff, I don't think that we have a Mozmill issue here. Or I'm not sure about which specific issue you are talking about. Marc, can you please run your example again with Firefox 3.6.x? Would be good to know if it is a regression between 3.6 and 4.0.

(In reply to comment #7) > Marc, can you please run your example again with Firefox 3.6.x? Would be > good to know if it is a regression between 3.6 and 4.0. After testing, I confirm that this is a regression between Firefox 3.6 and Firefox 4.0.

Marc, would you even have time to nail down the regression range to a specific date? That would be great.

(In reply to comment #9) > Marc, would you even have time to nail down the regression range to a > specific date? That would be great. Sorry, I cannot say more than between the release of Firefox 3.6 (January 21, 2010) and Firefox 4.0 (March 22, 2011) :-\ I even have had a hard time finding a 4.0 release on http://releases.mozilla.org/pub/mozilla.org/firefox/releases/ : there isn't any at the moment, so I tested with http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/4.0.1-candidates/build1/

Almost certainly a regression from bug 533038

(In reply to comment #11) > Almost certainly a regression from bug 533038 Bug 576492 put extension pref loading after user.js loading (which occurs during profile-do-change). http://hg.mozilla.org/mozilla-central/rev/a844e2a8c654

So, please, what's to do next with this bug report? I'm a bit at a loss. Has a fix arrived through other commits? Should I just try a nightly and report if it's actually fixed? Thank you!

Not fixed. And there's nobody assigned to it. I'll take it. Should be easy enough.

Removing "regressionwindow-wanted" because of comment 12.

(In reply to Michael Wu [:mwu] from comment #14) > I'll take it. Should be easy enough. Michael, do you have any news about the state of the patch for this bug? Can we get it fixed? I ask because we a blocked with some of our Mozmill tests for add-ons due to this behavior. Thanks.

I'm observing this problem with Firefox 11, and it prevents me from configuring default system-wide preferences for extensions.

Legacy extensions are no longer supported, and bug 1413413 removed the ability for extensions to have their own prefs file. So I believe this is no longer relevant.