Bug 443493

Summary: Certain windows or menu entries "stick to" the screen and cannot be removed without replacing kwin_x11
Product: [Plasma] kwin Reporter: Dipta Biswas <dabiswas112>
Component: compositingAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED DUPLICATE    
Severity: normal CC: nate
Priority: NOR    
Version: 5.22.5   
Target Milestone: ---   
Platform: Arch Linux   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:
Attachments: Ugly Xorg crap (context menu) covering active window

Description Dipta Biswas 2021-10-08 19:43:07 UTC
Created attachment 142261 [details]
Ugly Xorg crap (context menu) covering active window

SUMMARY
I keep using my PC normally. Then I close any program. Suddenly, kwin goes mad and the window "sticks to" my desktop with slightly lower opacity. It remains on top of other windows too.

STEPS TO REPRODUCE
1. Use PC normally
2. Close any program
3. Sometimes, the closed window "sticks", sometimes it doesn't

OBSERVED RESULT
See attachment. A "sticky" context menu is covering KRunner. Also happens with other windows (both KDE & non-KDE apps)

EXPECTED RESULT
The context menu shouldn't "stick" in the first place

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: 5.14.9-arch2-1
(available in About System)
KDE Plasma Version: 5.22.5
KDE Frameworks Version: 5.86.0
Qt Version: 5.15.2+kde+r237-1

ADDITIONAL INFORMATION
The bug is irregular though, like only 1-2% windows "stick" like that. Also it's not yet reproduced in Wayland. May also be an OpenGL or Xorg bug, but I'm a noob and Xorg source code on freedesktop seems spooky, so can't confirm that.
Comment 1 Dipta Biswas 2021-10-08 20:01:56 UTC
Well, think it's a KWin bug because `kwin_x11 --replace &` removes the "sticky" window. My compositor settings, if necessary, are as follows:
Scale method: Crisp
Rendering backend: OpenGL 3.1
Latency: Prefer lower latency
Tearing prevention ("vsync"): Only when cheap
Keep window thumbnails: Only for Shown Windows
Both `Enable compositor on startup` and `Allow applications to block compositing` are checked. Since no crash is involved, Dr Konqi doesn't come up to help me report a backtrace.
Comment 2 Nate Graham 2021-10-18 01:49:25 UTC

*** This bug has been marked as a duplicate of bug 439815 ***