Comment # 13 on bug 1149986 from Marcel Kuehlhorn

(In reply to Xu Zhao from comment #12)
> I have already found the root cause. In
> https://build.opensuse.org/package/view_file/KDE:Qt:5.13/libqt5-qtbase/
> libqt5-prioritise-gtk2-platformtheme.patch?expand=1 , openSUSE is
> prioritizing gtk2 theme over gtk3. This is incorrect. Given the time now
> gtk2 is mostly deprecated by both XFCE and Cinnamon, we should at least
> place gtk2 theme after gtk3.

Adding Dirk Mueller since he's bugowner of KDE:Qt to see if that would be
possible.