Bug 440154

Summary:	Firefox becomes unusable after compositing stops
Product:	[Plasma] kwin	Reporter:	Mufeed Ali <kdebugs.undead>
Component:	compositing	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED DOWNSTREAM
Severity:	normal	CC:	kde
Priority:	NOR
Version:	git master
Target Milestone:	---
Platform:	Compiled Sources
OS:	Linux
Latest Commit:		Version Fixed In:

Description Mufeed Ali 2021-07-22 12:11:21 UTC

SUMMARY

Crashing KWin, crashing compositing, using a fullscreen application that disables compositing, etc will make Firefox unusable and stuck at the last frame before the event.

STEPS TO REPRODUCE
1. Open Firefox
2. Play a full screen video with mpv (which disables compositing)
3. Exit full screen
4. Go back to Firefox

OBSERVED RESULT
Firefox will be stuck on the last frame before disabling compositing and will not be interactive

EXPECTED RESULT
Firefox should be normally usable

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Fedora 34 KDE
(available in About System)
KDE Plasma Version: 5.22.80
KDE Frameworks Version: 5.85.0
Qt Version: 5.15.2

ADDITIONAL INFORMATION
I've tested this with both KWin 5.22.3 and git master and both on Arch and Fedora as well. This is on Xorg, using the amdgpu driver with a Ryzen 2500U APU that has Radeon Vega 8 integrated graphics.

Comment 1 David Edmundson 2021-07-22 15:05:16 UTC

Then that's a firefox bug

Comment 2 Mufeed Ali 2021-07-22 15:54:04 UTC

Reported on Mozilla's Bugzilla instance: https://bugzilla.mozilla.org/show_bug.cgi?id=1721841

Comment 3 2wxsy58236r3 2021-07-23 00:10:32 UTC

Note that in Mozilla Ticket 1706934, [1] they want to refer this bug to KDE:

> Do you mind to report it at KDE bugtracker? (https://bugs.kde.org/) I don't think we have manpower to work on it.

[1] https://bugzilla.mozilla.org/show_bug.cgi?id=1706934#c3 (1706934 - Window content breaks for good with X11 EGL after suspending KWin compositing)