Bug 473594

Summary:	Custom Tiling sometimes doesn't work with Firefox Wayland (+workaround)
Product:	[Plasma] kwin	Reporter:	Loïc Droz <lk.droz>
Component:	Custom Tiling	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	REPORTED ---
Severity:	normal	CC:	dennis, inkbottle007, notmart
Priority:	NOR
Version First Reported In:	5.27.7
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Loïc Droz 2023-08-21 10:11:48 UTC

SUMMARY

Not sure if this is a Firefox or KWin issue, but attempting to tile a Firefox Wayland window (with shift+drag) *sometimes* does not work*. The tiling indicator shows up, but at the end of the drag, it stays where it was immediately before releasing mouse left. This only happens when I launch Firefox with MOZ_ENABLE_WAYLAND=1. Using just "firefox" launches it in XWayland mode, which does not have that issue.

* I found a WORKAROUND, which might help resolving that issue:

After the window fails to tile, switching to another virtual desktop, and then back to the original one, gets the window to tile properly.


STEPS TO REPRODUCE
1. Enable custom tiling
2. Start Firefox in Wayland mode with MOZ_ENABLE_WAYLAND=1 firefox
3. Shift+drag the firefox window to any desired custom tile, until the tiling indicator appears
4. Release mouse left, observe how the window did not tile.
5. If that did not trigger the bug, try again on a different tile.

OBSERVED RESULT

The window does not tile to the desired tile, instead it just keeps its position and dimensions as they were immediately before releasing mouse left.

EXPECTED RESULT

After releasing mouse left, the window should tile properly to the desired tile.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 6.4.11-arch2-1 (64-bit) / 5.27.7
KDE Frameworks Version: 5.109.0
Qt Version: 5.15.10

ADDITIONAL INFORMATION

Attached a screen capture of the bug and its workaround.

Comment 1 Loïc Droz 2023-08-21 10:12:51 UTC

Sorry the video is too heavy and attachment creation failed, you can view and download it here: https://kdrive.infomaniak.com/app/share/356870/a7b56ee8-172e-4d48-b444-1358be40abfb

Comment 2 Chris 2025-04-13 09:39:55 UTC

I'm experiencing this issue too.  
I'm not a fan of having to fall back on older technologies like X11/XWayland.  
I'm running Plasma 6.3.4 and hope that Plasma 6.4 will resolve this tiling bug.

Comment 3 Dennis 2025-06-30 06:26:52 UTC

Also experiencing this. I found another workaround: Tile other windows and then reactivate Firefox, it will tile to the same dimensions. For example, use brave and terminator to fill the full screen, enlarge the brave portion of the screen (the terminator tile will become smaller) and reactivate Firefox, it will tile to the dimensions of brave (or terminator depending on which part of the screen Firefox was). 

I'm not a dev, but let me know if I can do testing if needed. 

Details on my system:
Operating System: KDE neon User Edition
KDE Plasma Version: 6.4.1
KDE Frameworks Version: 6.15.0
Qt Version: 6.9.0
Kernel Version: 6.11.0-26-generic (64-bit)
Graphics Platform: Wayland
Processors: 24 × AMD Ryzen 9 5900 12-Core Processor
Memory: 32 GiB of RAM (31,2 GiB usable)
Graphics Processor: NVIDIA GeForce RTX 3070
Manufacturer: Alienware
Product Name: Alienware Aurora Ryzen Edition R14
System Version: 2.24.0

Comment 4 Dennis 2025-07-29 06:45:16 UTC

Seems to be fixed in my version. I can tile firefox the same way as other applications. I'm not using any parameters or env variables to start Firefox, just the default as KDE has given me. 

Operating System: KDE neon User Edition
KDE Plasma Version: 6.4.3
KDE Frameworks Version: 6.16.0
Qt Version: 6.9.1
Kernel Version: 6.14.0-24-generic (64-bit)
Graphics Platform: Wayland
Processors: 8 × Intel® Core™ i7-8565U CPU @ 1.80GHz
Memory: 16 GiB of RAM (15,3 GiB usable)
Graphics Processor: Intel® UHD Graphics 620
Manufacturer: Dell Inc.
Product Name: XPS 13 9380