Bug 511094

Summary: Breeze Cursors Broken above Size 48 (after upgrade to Plasma 6.5)
Product: [Plasma] Breeze Reporter: holyzolly
Component: generalAssignee: Plasma Bugs List <plasma-bugs-null>
Status: RESOLVED FIXED    
Severity: normal CC: nate, nicolas.fella, uhhadd
Priority: NOR Keywords: regression
Version First Reported In: 6.5.0   
Target Milestone: ---   
Platform: EndeavourOS   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description holyzolly 2025-10-25 13:37:47 UTC
SUMMARY
I am addressing the default Breeze cursors, I could not check any additionally installed cursors, because mine do not go above size 48.

STEPS TO REPRODUCE
1. Set cursor size above 48
2. Hit apply or logout/in or reboot and log in.

OBSERVED RESULT
Seems like only the upper right quarter of the cursor is shown is shown (with a "deinterlace" effect or "zebra crossing" from top to bottom or vertical lines in betwixt) 

EXPECTED RESULT
Usable cursor.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 6 5 0
KDE Plasma Version: 6 5 0
KDE Frameworks Version: the first one after 6.5 upgrade
Qt Version: 6.10*

ADDITIONAL INFORMATION
Enabled shake cursor effect. (also observed the bug when off)
Better Blur effect. (also observed the bug when off)
Klassy window decorations.
Bug also observed on X11.
Comment 1 Nate Graham 2025-10-25 15:43:42 UTC
I can't reproduce this myself. What kind of GPU are you using? Is it an older AMD GPU?
Comment 2 holyzolly 2025-10-25 17:33:55 UTC
(In reply to Nate Graham from comment #1)
> I can't reproduce this myself. What kind of GPU are you using? Is it an
> older AMD GPU?
Thanks for your quick reply.
No, a very old Nvidia one, nouveau-driven. NVD9 (Geforce 410M). I will reply once more if a .cache removal followed by a reboot solves it.
Comment 3 holyzolly 2025-10-25 20:02:33 UTC
It does not happen on X11, correction! However, flickering cursor but I think that's always been the case.

It does not happen because of the environment variables I had set KWIN_DRM_NO_AMS=1 or KWIN_FORCE_SW_CURSOR=0 or KWIN_FORCE_SW_CURSOR=1 ; I put them off now and rebooted.
KWIN_DRM_NO_AMS=1. 

It does happen on a new user on Wayland.

The only thing I can imagine what I altered cursor-wise is some file with Inherits=Breeze_snow, to get a persistent cursor on Flatpak. Maybe I gotta go that route?
Comment 4 Nate Graham 2025-10-27 17:20:47 UTC
Can you be clear about what exactly you changed? Does it happen with a default, unchanged cursor theme?
Comment 5 Nicolas Fella 2025-10-27 17:59:21 UTC

*** This bug has been marked as a duplicate of bug 510930 ***
Comment 6 holyzolly 2025-10-27 20:54:20 UTC
(In reply to Nate Graham from comment #4)
> Can you be clear about what exactly you changed? (2) Does it happen with a
> default, unchanged cursor theme? (1)

1) Yes it happens on a test user, but it is fine up to cursor size 48!

2) I set env. variables because I had a slower mouse in stacked windows, with the BetterBlur github effect https://github.com/taj-ny/kwin-effects-forceblur , where it is mentioned at the very bottom: in /etc/environment ...
"High cursor latency or stuttering on Wayland
This effect can be very resource-intensive if you have a lot of windows open. On Wayland, high GPU load may result in higher cursor latency or even stuttering. If that bothers you, set the following environment variable: KWIN_DRM_NO_AMS=1. If that's not enough, try enabling or disabling the software cursor by also setting KWIN_FORCE_SW_CURSOR=0 or KWIN_FORCE_SW_CURSOR=1."

I uncommented these 2 lines now. And now these slow-laggy-cursor issues are much better on 6.5 so that's a big plus: it is very fine for 3 or 4 stacked windows. But the 48+ bug is still there.

Somewhere down the lines I changed a config file to have a (consistent) Breeze Snow cursor on Flatpak browsers: 
/usr/share/icons/default/index.theme and put Inherits=breeze_snow
But as I see this has no influence on the bug I am facing (uncommented, rebooted)

3) Thanks for duplicate-mentioning, those lines in that pic I observe too on the panel (floating if that's a useful info)
Comment 7 holyzolly 2025-10-27 21:11:49 UTC
 observe too * around the cursor * on the panel.

I can screenshot the cursor too if needed.