Bug 464254

Summary: "Translucency" effect creates ghost windows when a window closes automatically
Product: [Plasma] kwin Reporter: Vagner Lunes <vagnerlunes>
Component: effects-variousAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED DUPLICATE    
Severity: normal CC: nate
Priority: NOR    
Version: 5.26.5   
Target Milestone: ---   
Platform: openSUSE   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description Vagner Lunes 2023-01-13 22:26:44 UTC
SUMMARY
Some applications have splash screens or update screens that will close automatically after they finish loading or updating their respective software (such as Krita, LibreOffice, Steam, Discord, etc..), sometimes I'll move these windows out of the way while working on some task, and as result these windows will sometimes close while they're being moved. 

I've found that while the "Translucency" Desktop Effect is active, this will cause a "ghost" duplicate of the window being moved to appear. It cannot be interacted with and will only disappear if compositing is toggled off. It will also be drawn over if another application takes focus and is brought to the top of the desktop, but won't disappear.

STEPS TO REPRODUCE
1. Open an application with a splash screen or auto-update start window
2. Move that window
3. Hold it in the moving state until it closes

OBSERVED RESULT
The window will disappear for a few frames and be replaced with a ghost window

EXPECTED RESULT
The window should disappear without any artifacts left behind

SOFTWARE/OS VERSIONS
Linux: openSUSE Tumbleweed
(available in About System)
KDE Plasma Version: 5.26.5
KDE Frameworks Version: 5.101.0
Qt Version: 5.15.8

ADDITIONAL INFORMATION
I initially suspected this to be a Wayland issue, as I had not experienced it while using X11, and I made the switch around three months ago. However, when logging into an X11 session I observed the same behaviour, but on X11 I could actually suspend the compositing to find that these ghost windows wouldn't be drawn with compositing off. That's what led me to narrow down that it was actually an issue with the "Translucency" Desktop Effect specifically.
Comment 1 Vlad Zahorodnii 2023-01-17 12:49:16 UTC

*** This bug has been marked as a duplicate of bug 441379 ***
Comment 2 Nate Graham 2023-01-17 16:41:45 UTC

*** This bug has been marked as a duplicate of bug 439332 ***