User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.6) Gecko/20100628 Ubuntu/10.04 (lucid) Firefox/3.6.6 Build Identifier: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.6) Gecko/20100628 Ubuntu/10.04 (lucid) Firefox/3.6.6 This bug report is a result of a discussion under the bug report: https://bugzilla.mozilla.org/show_bug.cgi?id=576749 It seems there are two separate Firefox Sync bugs, though they cause the same effect - they disable automatic connection of Sync at browser start. Reproducible: Always Steps to Reproduce: 1. Install User Agent Switcher extension: https://addons.mozilla.org/firefox/addon/59/ 2. Install Firefox Sync 1.4. 3. Restart a browser (one or several times) Actual Results: Firefox Sync doesn't connect at start. Expected Results: It should.

Reproducable in Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.3) Gecko/20100407 Ubuntu/9.10 (karmic) Firefox/3.6.3 This one seems platform (at least for linux) and version independent pending for more testing. As mentioned in the old bug report discussion https://bugzilla.mozilla.org/show_bug.cgi?id=576749#c36, this was also seen on Fedora 13.

Yeah, and I was able to reproduce it in Windows XP (32-bit) in VirtualBox.

I can confirm Vista SP2, Firefox 3.6.6 exhibits this bug. I have now removed UA switcher.

Okay, so UA switcher seems to prevent the overlay code from firing. UA switcher could just be slowing down window open enough to cause a race condition to go bad... for a workaround, create services.sync.autoconnectDelay as an integer pref, and set to 5 (in about:config)

Move weave:service:ready observer to the sync.xul overlay code (which is registered in chrome.manifest before overlay.xul). This reduces the chance of a race condition where weave:service:ready would be fired before the observer was registered. I have no idea exactly how reliable the new solution is compared to the old one, but it definitely fixes the reported problem. Also remove the weave:service:ready observer for Fennec completely and replace it with a default pref for autoconnectDelay.

Comment on attachment 456984 [details] [diff] [review] v1 r=me with one belt-and-suspenders fix: please set an autoconnectDelay value of 30 seconds for Firefox. delayedAutoconnect will update the timer with a different number if/when it fires, but if we still can trigger this race condition, we'll have a fallback.

Add belt-and-suspenders fix as suggested by mconnor.

This needs to go to both 1.4.x and default branches.

http://hg.mozilla.org/services/fx-sync/rev/8f705e5fabfe Move weave:service:ready observer to the sync.xul overlay code. This reduces the chance of a race condition where weave:service:ready would be fired before the observer was registered. Remove the weave:service:ready observer for Fennec completely and replace it with a default pref for autoconnectDelay. http://hg.mozilla.org/services/fx-sync/rev/fc96f8e6d3ea 1.4.x branch changeset

Please, add this fix for seamonkey path too

Verified with 1.4.1b3 on Fx3.6.7

(In reply to comment #10) > Created attachment 457475 [details] [diff] [review] [review] > fix for seamonkey too > > Please, add this fix for seamonkey path too Has this final part landed? Is the checkin-needed in the whiteboard still needed?

Philipp, please check what that checkin-needed was for, I moved it to the right place but seems just wrong.

Nah, this is ancient. All good.