This kdelibs patch prevents appearance of garbage in the scrollbars in Lightweight version 2 patch. Currently the rightmost pixel row in vertical scrollbars and bottom pixel row in horizontal scrollbars are not drawn. In KDE application this manifests in random appearance of a light line next to the scrollbar slider, but the most annoying this issue when using GTK-Qt-engine: in GTK apps the whole row becomes filled with garbage. This issue barred me from using Light_v_2 style.