Comment # 2 on bug 977040 from 6tr6tr R

(In reply to Wolfgang Bauer from comment #1)
> Created attachment 674412 [details]
> screenshot from an up-to-date Leap 42.1 VM, where it works
> 
> Works fine here, see attached screenshot.
> 
> Make sure your system is fully up-to-date.
> 
> This was indeed a "problem" in Plasma 5.4 as originally shipped with Leap
> 42.1 (IIRC), the taskmanager tried to lookup the icon in the application
> menu and fell back to the generic executable icon (i.e. the green "play"
> button you mentioned) if it couldn't find the corresponding entry for some
> reason (and this did happen with YaST in particular).
> There was an option in its settings to disable that though and always use
> the window icon.
> 
> It has been improved in 5.5 which we have released as official update for
> Leap 42.1, it should not use the generic fallback icon now.

This only partially fixed the issue. YAST now shows the icon, but my 3rd party
apps like IntelliJ still show the generic one. How can I get this working too?