Bug 502330

Summary: Firefox profile selection window overflows borders when dragged to second display with a different resolution and scaling
Product: [Plasma] kwin Reporter: TraceyC <kdedev>
Component: generalAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED DOWNSTREAM    
Severity: minor CC: nate
Priority: NOR Keywords: multiscreen, regression, wayland-only
Version First Reported In: git master   
Target Milestone: ---   
Platform: Solus   
OS: Linux   
See Also: https://bugs.kde.org/show_bug.cgi?id=491762
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: Firefox profile selection window

Description TraceyC 2025-04-02 18:22:55 UTC
Created attachment 179943 [details]
Firefox profile selection window

SUMMARY
When opening Firefox with `firefox -p` to choose a profile, the profile selection window contents will overflow the window borders if you drag it from one display to another - if the two displays have different resolution and scaling

This is reproducible in Plasma 6.3.3 as well as git-master

STEPS TO REPRODUCE
**System config**
At least two profiles in Firefox
Have two displays with different resolutions (reproduced with a laptop with a monitor connected via HDMI cable). Make sure at least one display is above 100% scaling (in my case it was the laptop)
This cannot be reproduced on my system if both displays are at 100% scaling

1. Run `firefox -p` to bring up the profile selection window
2. Drag the window from one display to the other, and back

OBSERVED RESULT
When on the display with 100% scaling, the window appears normally
When on the other display above 100% scaling, the contents overflow the window. The text briefly appeared stretched and fuzzy, before the text changed to look normal (but still overflowing the window container)

EXPECTED RESULT
The window contents remain clear, and within the window borders regardless of which screen the window is on

SOFTWARE/OS VERSIONS
Operating System: Solus 4.7
KDE Plasma Version: 6.3.3
KDE Frameworks Version: 6.12.0
Qt Version: 6.8.2
Kernel Version: 6.12.19-315.current (64-bit)
Graphics Platform: Wayland
Processors: 16 × 11th Gen Intel® Core™ i7-11800H @ 2.30GHz
Memory: 62.5 GiB of RAM
Graphics Processor 1: Intel® UHD Graphics
Graphics Processor 2: NVIDIA GeForce RTX 3060 Laptop GPU


ADDITIONAL INFORMATION
This wasn't an issue before Plasma 6.3.3, and I hadn't seen it until today despite running 6.3.3 for a while
This corresponds to updating Firefox today and restarting it (v137.0)
Comment 1 Nate Graham 2025-04-02 21:17:19 UTC
This is a Firefox bug. I encountered something nearly identical in Thunderbird a while back and it was their bug; see Bug 491762, and it's tracked on Thunderbird's size with https://bugzilla.mozilla.org/show_bug.cgi?id=1916537, which is still open

Very likely both apps share the same code that has this bug.