Bug 499388 - A small line briefly appears under the titlebar when maximizing a window, if specific combinations of titlebar button sizes and fractional scaling percentages have been set
Summary: A small line briefly appears under the titlebar when maximizing a window, if ...
Status: REPORTED
Alias: None
Product: kwin
Classification: Plasma
Component: decorations (other bugs)
Version First Reported In: 6.2.5
Platform: NixOS Linux
: LO minor
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2025-02-01 16:42 UTC by Luis
Modified: 2025-02-19 18:22 UTC (History)
4 users (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:


Attachments
Video showing the issue (2.67 MB, video/webm)
2025-02-01 16:42 UTC, Luis
Details
Update (239.72 KB, image/png)
2025-02-01 17:52 UTC, Luis
Details

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Description Luis 2025-02-01 16:42:57 UTC
Created attachment 177888 [details]
Video showing the issue

SUMMARY
Scaling: 125% + Font Size 10.5/8.5 + Tiny/Medium sized titlebar buttons = fine, any other titlebar button size = small transparent border when maximized for a split second, even with the default font size, similar behavior with the Very Large button size. Similar behavior even with integer font sizes.

STEPS TO REPRODUCE
1. Set font sizes and scaling as described on summary
2. Maximize and restore window
3. Witness the issue

OBSERVED RESULT
Border there for a split second.

EXPECTED RESULT
No border.

SOFTWARE/OS VERSIONS
Operating System: NixOS 25.05
KDE Plasma Version: 6.2.5
KDE Frameworks Version: 6.10.0
Qt Version: 6.8.1
Kernel Version: 6.13.0 (64-bit)
Graphics Platform: Wayland
Processors: 16 × 12th Gen Intel® Core™ i5-12500H
Memory: 23.2 GiB of RAM
Graphics Processor: Mesa Intel® Iris® Xe Graphics
Manufacturer: ASUSTeK COMPUTER INC.
Product Name: Vivobook_ASUSLaptop X1605ZA_X1605ZA
System Version: 1.0
Comment 1 Luis 2025-02-01 17:52:32 UTC
Created attachment 177892 [details]
Update

Actually, it's a transparent border.
Comment 2 John Kizer 2025-02-06 05:37:30 UTC
Hi - I'm afraid my eyesight isn't good enough to see what is being described in that video.

For others who may be able to see what you are, do you see the issue at any scaling settings other than 125%, or at any font sizes other than 8 or 10?

Thanks,
Comment 3 Luis 2025-02-07 01:41:12 UTC
(In reply to John Kizer from comment #2)
> Hi - I'm afraid my eyesight isn't good enough to see what is being described
> in that video.

You can see a small border appear and hide, it's like a border between the titlebar and the window contents. But it always is there actually, as shown in my second attachment.

> For others who may be able to see what you are, do you see the issue at any
> scaling settings other than 125%, or at any font sizes other than 8 or 10?

Seems to happen on 125%, 175%, not on 100% or 150%. And yes, seen it happen with sizes 12, 14 just now (window title font size).

> Thanks,
Comment 4 Luis 2025-02-07 01:47:34 UTC
Something interesting I just found out: Moving the mouse around the transparent border thingy makes it go away.