1273715 - Firefox first run page calls Mozilla.UiTour.getConfiguration() every ~2000ms

Status: RESOLVED WONTFIX

(Firefox :: Tours, defect)

Description

[Gregory Szorc [:gps]]

I started Nightly on a fresh profile on Windows to look at what system calls were being made. To my surprise, there were registry accesses to HKCU\Software\Classes\FirefoxURL\shell\open\command and similar every ~2000ms.

Some stack walking later reveals it is the first run web page sending an event to the UITour repeatedly. Probably a setTimer() that doesn't get unset or something.

I don't think this is a major performance issue. But I didn't look at the JS code too deeply to see what all it is doing. It certainly feels like the check it's doing only needs to occur once.

0 _sendEvent(action = [unavailable], data = [unavailable]) ["https://www.mozilla.org/media/js/firefox_win10_welcome-bundle.992fdcdf2a04.js":1]
1 Mozilla.UITour.getConfiguration(configName = [unavailable], callback = [unavailable]) ["https://www.mozilla.org/media/js/firefox_win10_welcome-bundle.992fdcdf2a04.js":1]
2 FirefoxDefault.isDefaultBrowser(callback = [function]) ["https://www.mozilla.org/media/js/firefox_win10_welcome-bundle.992fdcdf2a04.js":1]
3 Win10Welcome.checkForDefaultSwitch() ["https://www.mozilla.org/media/js/firefox_win10_welcome-bundle.992fdcdf2a04.js":1]

Comment 1

[Alex Gibson [:agibson]]

IIRC this is intentional as the page needs to check for if/when the user changes their default browser preference. Looking at the code, there is also a hard limit of 1000 retries before the polling stops, so this does seem like something that was considered on the initial outset.

https://github.com/mozilla/bedrock/blob/master/media/js/firefox/win10-welcome.js#L22

Going to close this as wontfix, but thanks for filing to bring to attention.