Created attachment 135958 [details] Application task bar: Three different windows, three identical icons SUMMARY While I use SeaMonkey (former Mozilla Application Suite <https://www.seamonkey-project.org/>), I have constantly open several windows: The browser, the mail reader, the mail composer and so on. Each type of window has distinguished application icon. Whereas I can see correct icons in task switcher (alt+tab) and window decorations (upper left corner), the icons on the task switching bar are wrong. All those different windows has just one icon - the main application logo. This is constantly confusing. STEPS TO REPRODUCE 1. Run SeaMonkey 2. Open different windows: browser and mailer 3. Check the taskbar OBSERVED RESULT All icons are the same - an application logo. EXPECTED RESULT Icons on the taskbar should reflect the window icon, not the application logo. SOFTWARE/OS VERSIONS Operating System: KDE neon 5.21 KDE Plasma Version: 5.21.0 KDE Frameworks Version: 5.79.0 Qt Version: 5.15.2 Kernel Version: 5.11.0-051100-generic OS Type: 64-bit Graphics Platform: X11 ADDITIONAL INFORMATION I've noticed the issue since I use Plasma 5 few years ago. This used to work earlier in KDE3/4. While it is just a minor issue (confusion) with icon+text task bar, it is a major usability issue for now-so-modern icon only task bar. Not sure about another apps behavior, as only few apps today are "one process, multiple windows". LibreOffice for example has correct icons.
Created attachment 135959 [details] Task switcher: Three different windows, three different (correct) icons
The Task Manager uses the icon specified in the app's .desktop file. The Task Switcher asks the window itself for what its icon should be. Arguably, the non-Icons-Only Task Manager should be doing what the Task Switcher does, to prevent these kinds of mismatches, since both are displaying windows, not apps. For the Icons-Only Task Manager, using the app icon makes more sense since it's designed to be listing apps, not windows.
On Wayland it's not possible to assign an icon to a window without a desktop file, which means this bug will have to be closed as intentional.
I don't follow. How is that relevant, and why can't the non-icons-only Task Manager do the same thing that the Alt+Tab Task Switcher is already doing? If the Task Switcher can do it, surely the Task Manager can also do it, no?
Because people who designed the wayland protocol had weird thoughts. That's it.
I don't understand what that means, sorry. Can you explain the technical details?