Bug 476341

Plasma 6 Wayland, today's git master. GPU hardware is an Intel 10th gen iGPU; drivers are from Mesa 23.1.9.


STEPS TO REPRODUCE
1. Have a laptop (it has a 4k screen normally run at 200% scale)
2. Plug in an external HDMI screen, either directly, or via a DisplayPort dongle (doesn't seem to make a difference)
3. Use the KScreen applet to invoke "Switch to External Screen" mode. The laptop screen correctly turns off.
4. Use the KScreen applet to invoke "Extend to left" or "Extend to right" modes, or use the KScreen KCM to manually mark the laptop screen as "Enabled"


OBSERVED RESULT
The laptop screen turns on, but it's lost its Plasma containment. All I see on it is the banner in the corner, and right-clicking on the black desktop does nothing. 


EXPECTED RESULT
Laptop screen turns on and its Plasma containment is shown.


ADDITIONAL INFORMATION
Restarting plasmashell or switching which display is marked as "Primary" does not fix the issue. It is not clear how to make the laptop display shows its containment again. For this reason, I'm marking the bug as Grave.


Here's the journal log from plasmashell after restarting it:

Oct 30 14:57:10 Liberator systemd[1884]: Starting plasma-plasmashell.service - KDE Plasma Workspace...
Oct 30 14:57:11 Liberator systemd[1884]: Started plasma-plasmashell.service - KDE Plasma Workspace.
Oct 30 14:57:11 Liberator plasmashell[8470]: file:///home/nate/kde/usr6/share/plasma/plasmoids/org.kde.desktopcontainment/contents/ui/main.qml:93: TypeError: Cannot call method 'elementSize' of null
Oct 30 14:57:11 Liberator plasmashell[8470]: file:///home/nate/kde/usr6/share/plasma/plasmoids/org.kde.desktopcontainment/contents/ui/main.qml:192:25: QML FolderViewDropArea (parent or ancestor of QQuickLayoutAttached): Binding loop detected for property "minimumWidth"
Oct 30 14:57:11 Liberator plasmashell[8470]: file:///home/nate/kde/usr6/share/plasma/wallpapers/org.kde.slideshow/contents/ui/main.qml:14:1: QML WallpaperItem: grabToImage: item's window is not visible
Oct 30 14:57:11 Liberator plasmashell[8470]: file:///home/nate/kde/usr6/share/plasma/wallpapers/org.kde.slideshow/contents/ui/main.qml:14:1: QML WallpaperItem: grabToImage: item's window is not visible
Oct 30 14:57:11 Liberator plasmashell[8470]: file:///home/nate/kde/usr6/share/plasma/plasmoids/org.kde.desktopcontainment/contents/ui/main.qml:93: TypeError: Cannot call method 'elementSize' of null
Oct 30 14:57:11 Liberator plasmashell[8470]: file:///home/nate/kde/usr6/share/plasma/plasmoids/org.kde.desktopcontainment/contents/ui/main.qml:192:25: QML FolderViewDropArea (parent or ancestor of QQuickLayoutAttached): Binding loop detected for property "minimumWidth"
Oct 30 14:57:11 Liberator plasmashell[8470]: qml: The backend got an unknown wallpaper provider type. The wallpaper will now fall back to the default. Please check your wallpaper configuration!
Oct 30 14:57:12 Liberator plasmashell[8470]: qml: SystemTray ItemLoader: Invalid state, cannot determine source!
Oct 30 14:57:12 Liberator plasmashell[8470]: kf.windowsystem: KWindowInfo is only functional when running on X11
Oct 30 14:57:12 Liberator plasmashell[8470]: QFont::setPointSizeF: Point size <= 0 (0.000000), must be greater than 0
Oct 30 14:57:13 Liberator plasmashell[8470]: file:///home/nate/kde/usr6/share/plasma/shells/org.kde.plasma.desktop/contents/views/Panel.qml:102:5: QML Connections: Detected function "onActivated" in Connections element. This is probably intended to be a signal handler but no signal of the target matches the name.
Oct 30 14:57:13 Liberator plasmashell[8470]: QObject::startTimer: Timers cannot be started from another thread
Oct 30 14:57:13 Liberator plasmashell[8470]: Connecting to deprecated signal QDBusConnectionInterface::serviceOwnerChanged(QString,QString,QString)
Oct 30 14:57:14 Liberator plasmashell[8470]: inotify_add_watch(/var/lib/samba/usershares) failed: (Permission denied)