Comment # 27 on bug 1037891 from Fabian Vogt

(In reply to Josef Reidinger from comment #25)
> (In reply to Fabian Vogt from comment #24)
> > (In reply to Josef Reidinger from comment #23)
> > > (In reply to Fabian Vogt from comment #22)
> > Maybe QCoreApplication::setApplicationName("YaST2") works here. As YaST does
> > not use QSettings, that shouldn't have any ill side effects
> 
> that is what we already doing, so title is correct, but for not known reason
> yet, no effect for icon
> 
> https://github.com/libyui/libyui-qt/blob/master/src/YQApplication.cc#L777
> 
> maybe we need to call also this
> qApp->setWindowIcon ( QIcon ( pixmap ) );
> to some predefined icon for yast, but I am not sure how it works with all
> modules, as it probably have own icons.

The icon is not the issue here, WM_CLASS is wrong.

In 42.2, where everything works fine, WM_CLASS = "YaST2", "YaST2", while in
42.3 and TW WM_CLASS = "ruby", "YaST2 - sw_single @ linux-lm3i.site"