Bug 514969

Summary: KAlarm window display corrupted
Product: [Plasma] kwin Reporter: Robert Kratky <kratky>
Component: wayland-genericAssignee: KWin default assignee <kwin-bugs-null>
Status: NEEDSINFO WAITINGFORINFO    
Severity: normal CC: fella, kdedev, kwin-bugs-null
Priority: NOR    
Version First Reported In: 6.4.5   
Target Milestone: ---   
Platform: Kubuntu   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: KAlarm, display corrupted

Description Robert Kratky 2026-01-23 10:58:28 UTC
Created attachment 188811 [details]
KAlarm, display corrupted

SUMMARY

The main KAlarm window is displayed with various weird corruption. See screenshot. This is after opening the window from the system tray. Closing and restarting the program fixes the problem.

AFAICT, this only happens after waking the system up from sleep.

STEPS TO REPRODUCE

1. Open KAlarm, minimize to system tray
2. Put system to sleep (suspend) and wake it up
3. Open KAlarm from the system tray

OBSERVED RESULT

See screenshot.

EXPECTED RESULT

No display corruption.

SOFTWARE/OS VERSIONS

Operating System: Kubuntu 25.10
KDE Plasma Version: 6.4.5
KDE Frameworks Version: 6.17.0
Qt Version: 6.9.2
Kernel Version: 6.17.0-8-generic (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 9 7940HS w/ Radeon 780M Graphics
Memory: 64 GiB of RAM (60,6 GiB usable)
Graphics Processor: AMD Radeon 780M Graphics
Manufacturer: Micro Computer (HK) Tech Limited
Product Name: Venus series
Comment 1 David Jarvie 2026-01-23 13:41:41 UTC
Does this happen with any other applications after waking from sleep?

I think that it must be a Wayland bug - there is no way that KAlarm itself could request its window to appear like you report.
Comment 2 Tobias Fella 2026-01-23 13:44:06 UTC
KWayland is a specific library that is (in general) is not the cause of wayland problems. Please do not put general wayland bug reports there
Comment 3 TraceyC 2026-01-23 15:41:21 UTC
Recategorizing as KAlarm.

Robert, are any other applications displaying with the same kind of window corruption?
Comment 4 David Jarvie 2026-01-23 18:50:21 UTC
@TraceyC: Could you please explain how you think an application could produce window corruption like this? I wouldn't have thought that it was possible, and that it must be the compositor or window manager or some such thing. That's why I reassigned it to Wayland.
Comment 5 TraceyC 2026-01-23 20:26:34 UTC
(In reply to David Jarvie from comment #4)
> @TraceyC: Could you please explain how you think an application could
> produce window corruption like this? I wouldn't have thought that it was
> possible, and that it must be the compositor or window manager or some such
> thing. That's why I reassigned it to Wayland.

I'm not one of the maintainers of Wayland or KWin (which does window compositing0, nor am I an application developer, so I can't tell you how an application can cause window corruption. In the HTML / CSS world I've seen that when libraries change, positioning can be thrown off and the code has to be updated to adapt. I don't know if that's the case here.

Tobias already confirmed this is not caused by KWayland, the library, so putting this back in that category isn't going to move this bug forward or get it in front of people who might be able to help. I'll move this to kwin, they can confirm whether this is a compositor bug or not.


Robert, please let us know if this happens with any other applications. Thanks.