Show wallpaper on non-translucent top-levels
requested to merge ninjalj/konsole:work/ninjalj/fix-477800-konsole-does-not-show-wallpaper-if-opacity-is-not-supported into master
For reasons, showing the background image (wallpaper) has become dependant on the ability of the top-level window to be translucent.
This does not need to be so. Since 5bac30ab, to draw the wallpaper, first a background color is used to fill the dirty region, and then the wallpaper is drawn, and the opacity of the background color and the wallpaper are separate, so we can fill with a totally opaque background color, and then draw a maybe translucent wallpaper over that, and no glitches should appear.