- Add keep-wallpaper-aspect-ratio-wallpaper-on-screen-resolution-change.diff:
* Chooses a new preferred background image when the screen
resolution is changed to keep the correct aspect ratio (boo#990257).
Also check for division by zero.

Note that for this patch to work correctly, it needs a kpackage with https://build.opensuse.org/request/show/433784 applied.