Created an attachment (id=691024) Readout of HTTP Header DEFECT DESCRIPTION: The browsers HTTP Accept header doe not contain the User Agent Profile URL. Actrually It's get in first time. But after reboot, The profile can't get. REPRODUCING PROCEDURES: EXPECTED BEHAVIOUR: ASSOCIATE SPECIFICATION: TEST PLAN REFERENCE: TOOLS AND PLATFORMS USED: USER IMPACT: REPRODUCING RATE: For FT PR, Please list reference mobile's behavior:

When I comment out /* SettingsListener.observe('wap.UAProf.url', '', function(value) { Services.prefs.setCharPref('wap.UAProf.url', value); });*/ in gecko/b2g/chrome/content/settings.js I can get wap.UAProf.url from user.js, which is what I want. That's mean, at first start up system/b2g/defaults/pref/user.js is read, but it's not set to data/b2g/mozilla/***.default/prefs.js. seems gecko/b2g/chrome/content/settings.js set a null to data/b2g/mozilla/***.default/prefs.js. and system/b2g/defaults/pref/user.js is never read.

Please see https://bugzilla.mozilla.org/show_bug.cgi?id=888821#c20

You can also refer to https://developer.mozilla.org/en-US/Firefox_OS/Developing_Firefox_OS/Market_customizations_guide#runtime_customization for more information.

weijia, Before bug 888821 landed, you can change UAProfURL by modifying user.js. After that, you should use the instructions in section "WAP user agent profile" in [1]. The code in settings.js is for hooking the preference with setting. You should not comment it out. John Hu already clear his idea in comment 20 of bug 888821 [2]. [1]: https://developer.mozilla.org/en-US/Firefox_OS/Developing_Firefox_OS/Market_customizations_guide#runtime_customization [2]: https://bugzilla.mozilla.org/show_bug.cgi?id=888821#c20