Bug 480092

Summary:	Task Switcher with Thumbnail Grid / preview crashes Kwin when compositor is turned off
Product:	[Plasma] kwin	Reporter:	Troplo <troplo>
Component:	effects-window-management	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED FIXED
Severity:	crash	Keywords:	qt6
Priority:	NOR	Flags:	troplo: X11+ troplo: NVIDIA+
Version First Reported In:	5.92.0
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:	https://invent.kde.org/plasma/kwin/-/merge_requests/4932	Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	Crash log of kwin_x11

Description Troplo 2024-01-20 11:26:45 UTC

Created attachment 165072 [details]
Crash log of kwin_x11

SUMMARY
When disabling the compositor with CTRL + SHIFT + F12, the task switcher is expected to fallback to icon-only mode as it did in Plasma 5, instead it must attempt to render the thumbnails which are unavailable with the compositor disabled causing the entire shell to crash and restart with the compositor re-enabled. I've been using Large Icons instead as my primary task switcher to circumvent this issue.

NVIDIA 545.29.06 on X11, Plasma 6 RC1 (Arch Linux)

STEPS TO REPRODUCE
1. Enable Thumbnail Grid or another switcher which shows thumbnails
2. Disable compositor
3. Watch the entire shell crash

OBSERVED RESULT
The shell crashes

EXPECTED RESULT
The switcher falls back to application icons instead of attempting to render preview

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 6.7.0-zen3-1-zen
KDE Plasma Version: 5.92.0
KDE Frameworks Version: 5.248.0
Qt Version: 6.7.0

ADDITIONAL INFORMATION
Crash log attached.
Video: https://i.troplo.com/i/3df5da04065d.mp4