Bug 438019

Summary:	When navigating away from "Global Theme" settings page, I get "Apply Settings" from "Window Decorations" page
Product:	[Applications] systemsettings	Reporter:	nyanpasu64 <nyanpasu64>
Component:	general	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	RESOLVED FIXED
Severity:	normal	CC:	mail, nate
Priority:	NOR
Version First Reported In:	5.21.90
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description nyanpasu64 2021-06-03 01:25:10 UTC

SUMMARY
When I open System Settings and navigate away from the "Global Theme" settings page

STEPS TO REPRODUCE
1. Edit Window Decorations settings, and change the "Window border size" away from "Theme's default" (I picked "Normal").
2. Open System Settings.
3. Click the Appearance tab in the sidebar. This opens "Global Theme" with a grayed-out Apply button.
4. Click any other tab in the sidebar, or press the back button and then click a tab.

OBSERVED RESULT
I get an "Apply Settings - System Settings" dialog, and *usually* the window contents (but not the sidebar) switches to the Window Decorations panel. Apply/Discard/Cancel have no effect (Apply does *not* reset "Window border size" to "Theme's default").

The bug can be repeated by closing and reopening System Settings, then repeating these steps. The bug does not occur if "Window border size" is set to "Theme's default".

EXPECTED RESULT
I don't get a spurious popup.

SOFTWARE/OS VERSIONS
Operating System: Arch Linux
KDE Plasma Version: 5.21.90
KDE Frameworks Version: 5.82.0
Qt Version: 5.15.2
Kernel Version: 5.12.8-arch1-1 (64-bit)
Graphics Platform: X11
Processors: 12 × AMD Ryzen 5 5600X 6-Core Processor
Memory: 15.6 GiB of RAM
Graphics Processor: NVIDIA GeForce GT 730/PCIe/SSE2

ADDITIONAL INFORMATION
I noticed visual flickering when switching to "Global Theme" to "Window Decorations". Is the Global Theme tab implemented by switching between the other pages and twiddling the values? The flickering feels hacky to me, since it suggests that editing the configuration is intertwined with switching GUI tabs.

Comment 1 Nate Graham 2021-06-08 22:50:39 UTC

I'm having a hard time following the steps to reproduce. In order to do step #1, you need to already be in System Settings, yet step #2 is "Open System Settings". Can you clarify?

Comment 2 nyanpasu64 2021-06-08 23:19:54 UTC

Correction:

1. Edit Window Decorations settings, and change the "Window border size" away from "Theme's default" (I picked "Normal"). Then close System Settings.

It's intended as a "setup step" that creates the right conditions for the bug to trigger every time you perform steps 2-4.

Comment 3 Nate Graham 2021-06-09 19:19:24 UTC

Thanks for the clarification. Cannot reproduce with those steps on current git master.

Comment 4 nyanpasu64 2021-06-10 17:35:37 UTC

Correction: at step 4, clicking Icons, Cursors, or Font Management do not reliably replicate this bug, and Colors usually but not always does. Is this a nondeterministic race condition?

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Another user in the #visualdesigngroup:kde.org Matrix encountered this bug as well, at https://matrix.to/#/!bigMeIySyPBfIAjBar:kde.org/$162333556821517oqGfx:kde.org?via=kde.org&via=matrix.org&via=tchncs.de. They built all of KDE from sources (from a recent git master? not sure).

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I have a second user account for testing, on Arch Linux running Plasma 5.22.0 plus a bunch of custom packages i built. I deleted .config and .local and .kde4 and a few other files, logged into KDE, and was able to reproduce this bug using my steps.

I was also able to reproduce this bug in GNOME Boxes, in an Arch Linux live CD .iso generated using https://aur.archlinux.org/packages/archuseriso/ with profile https://github.com/laurent85v/archuseriso/tree/master/profiles/kde (but with a trimmed-down package list at https://gist.github.com/nyanpasu64/aca7b29a3230f7c82a3d2d98444051ba, to generate a smaller .iso). If you want to download a .iso directly, there's http://dl.gnutux.fr/archuseriso/aui-kde-linux_5_12_9-0604-x64.iso (but it's over 2.4 gigabytes large).

Operating System: Arch Linux
KDE Plasma Version: 5.22.0
KDE Frameworks Version: 5.82.0
Qt Version: 5.15.2
Kernel Version: 5.12.9-arch1-1 (64-bit)
Graphics Platform: X11
Processors: 12 × AMD Ryzen 5 5600X 6-Core Processor
Memory: 3.8 GiB of RAM
Graphics Processor: llvmpipe

However I could not reproduce this bug in GNOME Boxes, running a KDE Neon live CD session with Plasma 5.22.0 (neon-user-20210610-0944.iso).

Operating System: KDE neon 5.22
KDE Plasma Version: 5.22.0
KDE Frameworks Version: 5.82.0
Qt Version: 5.15.3
Kernel Version: 5.4.0-74-generic (64-bit)
Graphics Platform: X11
Processors: 12 × AMD Ryzen 5 5600X 6-Core Processor
Memory: 3.8 GiB of RAM
Graphics Processor: llvmpipe

I'm wondering if each distro's default settings (beyond "Window border size") are another factor.

Comment 5 Nate Graham 2025-10-09 17:05:40 UTC

Still can't reproduce, and there's been a major re-org of System Settings since then, with lots of code changes. Let's assume this one was fixed; can you open a new bug report for any issues you still encounter? Thanks a lot!