unity regularly gets confused about Firefox's window

[Chow Loong Jin]

From time to time (I don't know when, it seems to happen at random intervals), Unity starts getting confused about Firefox's window state. Below are the symptoms:-

1. Firefox, although maximized, no longer has its menu showing up when the pointer is over the Unity panel. Likewise, its window title no longer appears in the panel. When the Firefox window is focused and maximized, the panel is blank where the window buttons and menu or title should be, whether or not the pointer is hovering on the panel).
2. The Firefox icon on the Unity launcher shows a filled triangle on the right side, but an empty triangle on the left side, which seems to indicate that Firefox's window is focused, although not on the current workspace.
3. Alt+Tab orders Firefox's window to the back of the list (alt_tab_bias_viewport = true).
4. Alt+Grave over Firefox's icon causes Compiz to segfault (I should have gotten a stack trace; I'll do that next time).
5. Selecting Firefox's icon from Alt+Tab does nothing.
6. Clicking Firefox's launcher in the sidebar does nothing.

And here's the weird part: Other application switchers in Compiz, e.g. Ring switcher, and Scale, work as expected. Scale even properly detects the workspace that Firefox is on, judging from the [N] suffix to Firefox window's title. This indicates that the bug is probably not in compiz, but in Unity or something it uses.

All of the above symptoms are for one issue. The symptoms either appear all at once, or not at all. The only way to get rid of this seems to be to restart Unity or the application in question (Firefox)

ii firefox-trunk 10.0~a1~hg20111018r78888-0ubuntu1~umd3 Safe and easy web browser from Mozilla
ii unity 4.24.0-0ubuntu2 Interface designed for efficiency of space and interaction.

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: unity 4.24.0-0ubuntu2
Uname: Linux 3.0.4-ck1-hyper1 x86_64
ApportVersion: 1.23-0ubuntu3
Architecture: amd64
CompizPlugins: [core,bailer,detection,composite,opengl,decor,snap,move,commands,resize,annotate,resizeinfo,gnomecompat,text,obs,mousepoll,regex,place,widget,extrawm,vpswitch,grid,clone,compiztoolbox,imgpng,session,showmouse,put,wall,ring,screenshot,unitymtgrabhandles,animation,workarounds,fade,showdesktop,expo,scale,ezoom,scaleaddon,scalefilter,unityshell]
Date: Thu Oct 20 10:46:43 2011
SourcePackage: unity
UpgradeStatus: Upgraded to oneiric on 2011-10-14 (6 days ago)

[Bilal Akhtar (bilalakhtar)]

I can't reproduce this bug on my system. I'm marking this Incomplete for now, please mark this new again when you've acquired the stack trace. If the issue doesn't occur again at all, then please leave a comment here.

[Chow Loong Jin (hyperair)]

Stack trace? I'm not sure what kind of stack trace you would be looking for, as it's not a crash or a hang or anything. It's just that Unity gets confused about the state of Firefox's window, but otherwise continues running fine. Closing the Firefox window sometimes gets it to work properly again. Stack traces at this point would probably be useless as they would just show Compiz in its normal mode of operation.

[Chow Loong Jin (hyperair)]

For the record, this bug still happens from time to time, but I am still not able to pinpoint a method of forcing Unity to reproduce the issue.

[Omer Akram (om26er)]

steps to reproduce would be helpful, maybe a few screenshots would also help..

about issue 1. does that happen after spread (super+w) ?

issue 3. thats a general bug I believe not specific to firefox.

4. stack trace or better enable apport and report with the .crash file in /var/crash for easy duplication ;-)

Basically all these issues cannot be treated as a single report. they are different issues which are not specific to Unity as I have seen similar issues reported for different apps.

[Chow Loong Jin (hyperair)]

Everything I know is in the description. All the symptoms are related, and happen *only* when this happens to an application. As you said, it's not specific to Firefox, just that Firefox seems to be the application that triggers it most often. It's *one* issue, with multiple symptoms, that only affects Unity. The spread/scale switcher don't have any issue, nor any other switcher.

About the Alt+grave segfault (4), I think it doesn't happen any more after several unity updates in oneiric-updates, or at least, I haven't noticed it crashing from that scenario.

As for steps to reproduce, as I have mentioned earlier, I have no idea how to trigger this bug. It just happens.

[Omer Akram (om26er)]

Is bug 897344 one of the issues you facing?

[Chow Loong Jin (hyperair)]

On 06/12/2011 20:56, Omer Akram wrote:
> Is bug 897344 one of the issues you facing?

Yes, it's the same issue.

But please note: there is only *one* issue described in this bug -- presumably
Unity having a bad internal representation of Firefox's window's state (it
thinks that it's on a different workspace, but that's not the case).

--
Kind regards,
Loong Jin

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Chow Loong Jin (hyperair)]

Alright, I've reproduced this issue with a Banshee window, and have taken a series of screenshots to explain my observations:-

1. As you can see in unmaximized.png, the Banshee window is focused, but the left triangle for the Banshee icon is empty, indicating that it isn't in the current workspace (although it really is).
2. In maximized.png, you can see that the window title is missing from the panel, although the Banshee window is focused.
3. In expo.png, you can see that Banshee is in workspace 8, and that is the current workspace.
4. In menubar.png you can see what happens when you hover the cursor over the panel -- the wrong menubar appears. That menubar is meant for Thunderbird, which is in workspace 9.
5. In ring switcher (all workspaces).png, you can see that the ring switcher allows for switching to the Banshee window, and that it is on workspace 8 as shown by the -[8]- suffix. This also shows that the ring switcher knows (correctly) which workspace Banshee's window is on.
6. In scale expanded.png, produced from right clicking a window in scale/spread switcher mode, same observation as from #5.

Apport crash will be uploaded shortly.

[Marko Vendelin (marko-vendelin)]

I have encountered the same bug in 11.04 . Sometimes it helps to open a new firefox window and close it on the desktop with the maximized firefox window that is without the focus. As a result, the original window regains the focus. However, this trick has to be repeated frequently to regain the focus after working with other windows/desktops.

[Evan Huus (eapache)]

Just hit this for the very first time on an up-to-date precise. Will try to figure out how to reproduce reliably.

[Chris Kaye (flux-incapacitor)]

I'm not sure if my issue is related or not, but for me:
Firefox has no triangle at all, to show that it is open.
Neither does it show up in the Alt-Tab list, whatever work space I'm in.
Clicking on the Firefox button opens a new firefox window.

I haven't tried restarting my computer yet though, so that may fix it...

[Stephen M. Webb (bregma)]

@Chris Kaye

This bug was originally reported in Ubuntu 11.10 (which is no longer under support). Which version of Ubuntu are you experiencing this on?

[Alex Baggott (alex-baggott)]

Thank you for taking the time to report this bug. We have tried to recreate this on the latest release of Ubuntu and cannot reproduce it. This bug is being marked as Invalid. If you believe the problem to still exist in the latest version of Ubuntu please comment on why that is the case and change the bug status to NEW.