Bug 480362

Summary:	Mouse hover is not stable on the left side of screen if you keep pushing the cursor to the left
Product:	[Plasma] kwin	Reporter:	ratijas <me>
Component:	general	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	REPORTED ---
Severity:	normal	CC:	nate
Priority:	NOR	Keywords:	qt6
Version First Reported In:	git master
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:
Attachments:	cursor at the screen edge

Description ratijas 2024-01-26 15:01:10 UTC

SUMMARY

In some apps, window content repeatedly changes hovered/unhovered state on the left edge, even though mouse is not supposed to leave window bounds.

STEPS TO REPRODUCE
1. Snap a window to the left side of the screen
2. Move the cursor the left, and keep moving/pushing it toward the edge.

OBSERVED RESULT
In Firefox (with Tree Style Tab plugin sidebar) and Sublime HQ apps, list item under mouse cursor hovers/unhovers repeatedly in response to mouse "movement" toward the edge, as if the cursor were briefly moving 1px outside the screen bounds, and then immediately gets pushed back in.

EXPECTED RESULT
Expected stable and robust window & screen boundaries.

SOFTWARE/OS VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 6.0.80
KDE Frameworks Version: 5.249.0
Qt Version: 6.6.1
Kernel Version: 6.7.0-arch3-1 (64-bit)
Graphics Platform: X11
Processors: 8 × Intel® Core™ i7-6700HQ CPU @ 2.60GHz
Memory: 15.6 GiB of RAM
Graphics Processor: NVIDIA GeForce GTX 970M/PCIe/SSE2

reproducible on Plasma 5 & 6

Comment 1 ratijas 2024-01-26 15:01:37 UTC

Created attachment 165250 [details]
cursor at the screen edge

Comment 2 ratijas 2024-01-26 15:05:25 UTC

Doesn't seem to be happening on the bottom or right sides. Not sure how to test the top edge.

Comment 3 ratijas 2024-01-26 15:06:25 UTC

No fractional scaling. 100% FullHD 1920x1080 screen only.

Comment 4 Vlad Zahorodnii 2024-01-29 12:17:12 UTC

> Graphics Platform: X11

Is this correct? Can you check if the issue is reproducible when running without kwin_x11?