warn the user when setting an invalid/non-image file as background image file
Submitted by Szekeres Istvan
Description
It seems like when a non-existing background image is specified for gnome-terminal, the terminal background is painted white. In my case I just selected Effects->Background image in the profile editor, but left the filename untouched (it was the name of my home directory, not a real file). This didn't cause any visible change in the already existing terminal windows, but when I opened up a new one, I just saw a totally white window without the prompt and cursor. My original color scheme was white on black, so basically what I got was white on white.
I think if the background image is specified incorrectly, the normal ("None") background should be used.
Resolution: RESOLVED OBSOLETE