Fullscreen game windows vertically offset after returning from Alt-Tab

[Jeremy Bícha]

Impact
======
Using Alt-Tab to leave a fullscreen game and then return breaks the game by offsetting the display by the size of the GNOME Shell top bar (and the Ubuntu Dock if running).

Test Case
=========
1. Log into the default Ubuntu session. (Make sure that Wayland is running by running this command. If you have output, you are running Wayland.

env | grep -i wayland

2. Run a game full screen.

I installed Steam and used Team Fortress 2 because it's free (but a very large download)

3. Press Alt-Tab to switch to another window and then press Alt-Tab to switch back to the game.

The game should display and function normally.

Workaround
==========
Open the Activities Overview and click the game window instead of using Alt-Tab to switch back to the game.

Other Info
==========
This bug is split from LP: #1725649 where the problem was seen and fixed for the Xorg session. This bug is for the Wayland sessions.

[Eero-t-tamminen (eero-t-tamminen)]

Note that Mutter fullscreen handling isn't fully fixed even for Xorg, see bug 1755501.

(It's not a regression, at least not a recent one, but something that works fine with all other desktops. I think any use-case which doesn't support resizing after it opens its non-resizable fullscreen window, would suffer from the same Mutter bug.)

[Daniel van Vugt (vanvugt)]

Thank you for reporting this bug to Ubuntu.
Ubuntu 17.10 (artful) reached end-of-life on July 19, 2018.

See this document for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases

We appreciate that this bug may be old and you might not be interested in discussing it any more. But if you are then please upgrade to the latest Ubuntu version and re-test. If you then find the bug is still present in the newer Ubuntu version, please add a comment here telling us which new version it is in and change the bug status to Confirmed.

[Harald H. (haarektrans)]

Please also see upstream reports: https://gitlab.gnome.org/GNOME/mutter/issues/397

[maarten (info-maartenabbring)]

Regression: when upgrading from ubuntu 19.04 to 19.10 this bug is back

[maarten (info-maartenabbring)]

Bug doesn't appear anymore on ubuntu 19.10, mutter packages are now at 3.34.1-1ubuntu1

[Daniel van Vugt (vanvugt)]

It sounds like this bug was fixed before Ubuntu 20.04 was released. Can anyone else confirm?

[Akbarkhon Variskhanov (kbar)]

Hey, Daniel! You sent me here from #1890281

#1725649 is said to be fixed but the bug is still present on Ubuntu 18.04.4 running X. I've recently upgraded to Bionic and noticed this bug immediately as I often play games.

Shall I file a new bug report?

Thanks in advance.

[Daniel van Vugt (vanvugt)]

This bug is open again now so we don't need another report. Thanks.

[Akbarkhon Variskhanov (kbar)]

Thanks for the quick response!

Another detail I want to add is that it only happens after invoking the switcher. I can control volume or screen brightness all good without any problems but as soon as I switch windows and go back to my game the top bar keeps appearing whenever the volume or screen brightness controls are accessed. The switcher is definitely the culprit here.

It happens on X, it happens on Wayland. On X, the bar usually disappears as soon as the switching animation stops or volume and screen brightness control pop-ups fade away. On Wayland, the bug persists until I re-open the affected window through Activities, not the Switcher.

GNOME Shell 3.28.4-0ubuntu18.04.3
Mutter 3.28.4-0ubuntu18.04.2

[Daniel van Vugt (vanvugt)]

I think this bug might have already been fixed before Ubuntu 20.04 was released. So there's another reason to upgrade :)

[Akbarkhon Variskhanov (kbar)]

I found a work-around: disabling animations in GNOME Tweaks solves the issue and the whole Top Bar (not a ghost of it) and the Dock are visible for a very short time until the window becomes fullscreen.

I suggest to include an option to disable these animations when fullscreen windows are present because they also cause frame drops.

As for upgrading I'm patiently waiting for the dot release. Fingers crossed tomorrow is the day. :)

[Daniel van Vugt (vanvugt)]

Thank you for reporting this bug to Ubuntu.

Ubuntu 18.04 (bionic) reached end-of-standard-support on May 31, 2023.

See this document for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases

We appreciate that this bug may be old and you might not be interested in discussing it anymore. But if you are then please upgrade to the latest Ubuntu version and re-test. If you then find the bug is still present in the newer Ubuntu version, please add a comment here telling us which new version it is in.