Comment 2 for bug 1312577

Steps to reproduce:
- dual monitor setup, main (larger) monitor is set to the left of the laptop screen.
- wallpaper on main monitor is in spanning screens mode, and the image exactly fits both screens
- change the image file on disk
- execute xfdesktop --reload

Expected:
The image is reloaded from disk, and I see my new image on both screens.

What happens:
The wallpaper from the second screen (that was not visible because the first one spans on top of it) is now on both screens.

Seems as if there should be a conditional break in the wallpaper reload code that only paints the spanned wallpaper, and ignores the others.