[Qt Wayland] `ui_dialogs_in_taskbar__linux` = `false` doesn't work

[pintassilgo]

1. Wayland session.
2. Launch Cuda Qt (both official Qt5 and Flatpak Qt6 are affected).
3. Set ui_dialogs_in_taskbar__linux = false and restart Cuda to make sure the change is applied.
4. Open Command palette.

Expected:

Command palette shouldn't be treated as a separated window i.e. it shouldn't appear as a new window in taskbar, also if you press Alt + Tab you should activate a window of a different app (like webbrowser or whatever).

Current:

Command palette opens as a separated window, with its own tab in taskbar, also if you press Alt+Tab you activate Cuda window, minimizing Command palette.

Gtk is not affected.

I use KDE Plasma, but hopefully any DE running Wayland session is affected when you run Qt Cuda.

Currently, I run Cuda with QT_QPA_PLATFORM=xcb set to avoid this issue. By doing this, I'm launching Cuda as xwayland window instead of native Wayland, so I shouldn't do it. And Cuda xwayland has its own bugs like #5132.

[Alexey-T]

  UiOps.PluginDialogsShowInTaskbar:= cfg.GetValue('ui_dialogs_in_taskbar'+cOptionSystemSuffix, UiOps.PluginDialogsShowInTaskbar);

so, option is applied only to UiOps.PluginDialogsShowInTaskbar which is applied only to PLUGINS dialogs. Cmd Palette is not affected by this flag. it has "never show in taskbar" option. if it shows in taskbar, it seems a Lazarus bug.
I cannot see it on Ubuntu 20 with Gnome, Wayland too, qt5 too.

[pintassilgo]

option is applied only to UiOps.PluginDialogsShowInTaskbar which is applied only to PLUGINS dialogs. Cmd Palette is not affected by this flag

Find favorite..., dialog from Favorites plugin, is also affected i.e. creates tab in taskbar, acts as a separated window.

[Alexey-T]

Primitive demo for qt5:

tst-ShowInTaskbar-qt5.zip

run 'project1' app.

press button 2-3 times. do all new windows (created by button) have style "show in taskbar"? they have it "NEVER show in taskbar".

[pintassilgo]

Yes.

[Alexey-T]

Pls show me system info. maybe run 'neofetch'.

[pintassilgo]

This is Wayland-only issue. If I run as xwayland i.e. not true Wayland app, there's no issue.

[Alexey-T]

'neofetch'? what does it show.

[pintassilgo]

Operating System: openSUSE Tumbleweed 20240310
KDE Plasma Version: 5.27.10
KDE Frameworks Version: 5.115.0
Qt Version: 5.15.12
Kernel Version: 6.7.7-1-default (64-bit)
Graphics Platform: Wayland
Processors: 12 × AMD Ryzen 5 1600 Six-Core Processor
Memory: 31,3 GiB of RAM
Graphics Processor: AMD Radeon RX 570 Series

[Alexey-T]

Bugreport for Lazarus
https://gitlab.com/freepascal.org/lazarus/lazarus/-/issues/40954