Bug 499329

Summary:	remembering virtual desktop per activity is extremely unreliable
Product:	[Plasma] kwin	Reporter:	Oded Arbel <oded>
Component:	activities	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED WORKSFORME
Severity:	normal	CC:	nate, xaver.hugl
Priority:	NOR
Version First Reported In:	git master
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:
Attachments:	screen cast showing the reproduction

Description Oded Arbel 2025-01-30 14:37:53 UTC

SUMMARY
After remembering the virtual desktop for each activity has moved from activitymanaged to kwin (https://invent.kde.org/plasma/kwin/-/merge_requests/5871), the feature is misbehaving pretty badly: which VD you'd end up on when switching activities - looks pretty random (in day to day, where after I land in the wrong VD, I change to where I want, then get into additional trouble when I switch activity again).

When switching activities back and forth, without switching VDs in between - there is some logic to how it operates, which looks like rather simple:

STEPS TO REPRODUCE
1. Setup up two activities with 4 virtual desktops.
2. Switch to activity B and move to VD 3. Switch to Activity A and move to VD 1.
3. Switch activities back and forth.

OBSERVED RESULT
- Switch to B: VD 3 with VD switching animation
- Switch to A: VD 1with VD switching animation
- Switch to B: VD 1 with VD switching animation
- Switch to A: VD 3 with VD switching animation
- Switch to B: VD 1 with no VD switching animation
- Switch to A: VD 1 with VD switching animation
... lather rinse repeat

EXPECTED RESULT
The virtual desktops should switch automatically and always be VD 1 on activity A and VD 3 on activity B.

SOFTWARE/OS VERSIONS
Operating System: KDE neon Testing Edition
KDE Plasma Version: 6.2.90
KDE Frameworks Version: 6.11.0
Qt Version: 6.8.1
Kernel Version: 6.8.0-52-generic (64-bit)
Graphics Platform: Wayland
Processors: 20 × 12th Gen Intel® Core™ i7-12700H
Memory: 31.0 GiB of RAM
Graphics Processor: Intel® Graphics

ADDITIONAL INFORMATION

Comment 1 Oded Arbel 2025-01-30 14:38:32 UTC

Created attachment 177824 [details]
screen cast showing the reproduction

Comment 2 Oded Arbel 2025-01-30 14:40:30 UTC

Maybe see also bug #498788 that I opened with the wrong description and before I had a really good reproduction.

Comment 3 Zamundaaa 2025-01-30 16:55:38 UTC

There should never be a VD switching animation when switching between activities, something aside from KWin is messing with things.

Please check that ~/kde/usr/plugins/kactivitymanagerd1/org.kde.ActivityManager.VirtualDesktopSwitch.so does *not *exist (for a system-wide installation, it's likely in the /usr/lib64/qt6/plugins/kactivitymanagerd1/ folder)

Comment 4 Oded Arbel 2025-01-30 19:02:17 UTC

(In reply to Zamundaaa from comment #3)
> Please check that
> ~/kde/usr/plugins/kactivitymanagerd1/org.kde.ActivityManager.
> VirtualDesktopSwitch.so does *not *exist (for a system-wide installation,
> it's likely in the /usr/lib64/qt6/plugins/kactivitymanagerd1/ folder)

There's `/usr/lib/x86_64-linux-gnu/qt6/plugins/kactivitymanagerd1/org.kde.ActivityManager.VirtualDesktopSwitch.so` installed as part of kactivitymanagerd 6.2.5+p24.04+vstable+git20250109.2216-0 from http://archive.neon.kde.org/testing noble/main amd64

I will try to manually remove it and repro again.

Comment 5 Oded Arbel 2025-01-30 19:06:29 UTC

After sudo rm -f the plugin file, the VD switching seems stable and as I expect.

There is still some kind of animation - the shell wallpaper sliding, though not the windows - but only when switching from the first activity to the second, and not the other way. But the main issues seems to be that org.kde.ActivityManager.VirtualDesktopSwitch.so existed.

I'm assuming the kactivitymanagerd side of the change, on my system, didn't get the memo yet and will be updated when Neon testing gets it shit together.