1502949 - application icon disappearing for some users on 63 update

Status: NEW

(Firefox :: Installer, defect, P3)

Description

[Asa Dotzler [:asa]]

https://twitter.com/Xaobotnik/status/1056859135323582464
https://twitter.com/jwd50/status/1055116983442829319

I've seen a couple of reports of people losing their Firefox launcher icons with the update to 63. One report mentioned the taskbar icon disappearing. The other mentioned the taskbar and desktop icons both disappearing.

Comment 1

[Molly Howell (she/her) (mostly inactive)]

There was only one patch to any code that affects taskbar shortcuts during 63, bug 1485484, but I don't really think that would have caused this, plus occasional reports about disappearing taskbar pins seem to come in even for releases that don't have any changes to that code at all. So I think either we have a very old and subtle bug in our taskbar shortcut handling, or there's some environmental/third-party software interaction that we're not aware of.

One thing we could try is to adopt a policy of making absolutely sure we never issue any writes to the taskbar shortcut file when we can tell that don't have any actual changes we need to make to it (not having any changes is the typical case). We know that certain kinds of modifications (renaming) can cause the shell to forcibly unpin the shortcut without deleting the file, but there is no documentation about this behavior, so the only safe thing to do is avoid doing anything.

(In reply to Asa Dotzler [:asa] from comment #0)
> The other mentioned the taskbar and desktop icons both disappearing.

The desktop shortcut seems like a different situation where there really has to be some third party thing involved; taskbar pins are fragile because they consist of a file and also some undocumented and obfuscated registry entries that the shell can do whatever it wants with, but desktop shortcuts are only a file, plus we've had them forever, so I have a harder time believing we're responsible for breaking those.

Comment 2

[Matthew N. [:MattN]]

Are there installer/updater logs on the filesystem that would be useful in this case? My mom saw this on her Windows 10 computer but she tried to fix things before she told me so I wasn't actually sure what happened.

Comment 3

[Molly Howell (she/her) (mostly inactive)]

The aren't, unfortunately. I filed bug 1497271 recently for adding exactly that log, because there was another issue that made it clear how useful that would be, but I haven't had a chance to work on it.