Created attachment 156751 [details] pinned icon disappears then appears again SUMMARY In plasma wayland session, "Telegram Desktop"'s icon pinned in task manager disappears when its window was closed, if you have selected any chat after openning the window. The window's title would change to the contact name when you select a chat, maybe that's the cause ... STEPS TO REPRODUCE 1. Install telegram-desktop (version 4.6.5, from https://desktop.telegram.org/ ) 2. Launch the app, login, pin it's icon to Icons-Only task manager 3. Click that pinned icon to open its main window, then select any chat 4. Close the window OBSERVED RESULT The pinned icon disappears in Icons-Only task manager, then appears again after several seconds. EXPECTED RESULT The pinned icon should not disappear. SOFTWARE/OS VERSIONS Linux/KDE Plasma: KDE Plasma Version: 5.27.1 KDE Frameworks Version: 5.103.0 Qt Version: 5.15.8+kde+r181-1 ADDITIONAL INFORMATION
Can reproduce. Possibly a Telegram bug. Of note, I've disabled the System Tray icon so that closing the window quits the app entirely.
I don't quite understand how that could be a Telegram, could you elaborate please?
I haven't a clue. But the issue is only seen with Telegram.
Similar bug confirmed with Lutris: https://github.com/lutris/lutris/issues/4817. Reproduced on Plasma 5.27.4 with Telegram and Lutris.
I can't reproduce this issue with plasma 5.27.5 and telegram-desktop 4.8.1. Maybe it has been fixed somehow?
Me neither. Looks a change in Telegram fixed it, at least for that app. Still, there's probably a general issue with the Task Manager code here that gets triggered by certain app behaviors.
Telegram is not aware about that icon at all
It's not about the icon per se, it's about the Task Manager's ability to map an app's window to its pinned launcher icon. It's possible for windows to change their metadata enough that this internal mapping breaks, and then the issue as described here can happen.
I would except something like a duplicate icon if that's the case. What happens on the video looks like some lag in Plasma to me.
Ah, I remembered a thing: tdesktop forces Qt to compose via OpenGL by overriding QWidgetPrivate::rhiConfig since 4.8.0 as various compositors (e.g. mutter) have bad compatibility with Qt's wl_shm implementation. Maybe Plasma has performance problems with (frameless?) wl_shm windows.
Maybe it's not just due to frameless but also the transparency. I guess Lutris window is both frameless and transparent as well.
I've observed this same bug today with Chromium 122.0.6261.128 and Plasma 6.0.3 with a slightly different twist. The icon disappears when I open Chromium and close it before the bouncing icon next to the cursor disappears. Additionally, if Chromium is open in another virtual desktop, the icon does not disappear. Note: The icon bouncing next to the mouse cursor for long after the application is actually open is something I've only seen happening with Chromium, and it might be a linked issue. It appears Telegram also had issues with the bouncing icons.