Comment # 31 on bug 1149986 from Fabian Vogt

(In reply to Xu Zhao from comment #30)
> (In reply to Fabian Vogt from comment #29)
> > (In reply to Marcel Kuehlhorn from comment #28)
> > > (In reply to Xu Zhao from comment #27)
> > > > Just curious, why does openSUSE still have the gtk2 priortise patch in libqt5-qtbase? It doesn't make any sense to me to still favor gtk2 theme over gtk3 on Qt applications. Removing this patch will solve this problem automatically, based on my understanding of this bug.
> > > 
> > > Good question, maybe one of the maintainers could answer that?
> > 
> > The gtk3 plugin is only a platform plugin, but not a theme or style, so it
> > would use Fusion (or some other theme) with GTK 3 dialogs. The gtk2 style
> > plugin is a complete style, theme and platform plugin.
> 
> I see. Sorry I am not familiar with this part of Qt. Could you please
> provide more details? Why prioritzing gtk3 platform plugin and using other
> gtk3 theme over gtk2 style plugin(w/ theme and style) is a problem?

Qt does not support GTK3 themes, only GTK2 ones.