Broken: 2.79 5bd8ac9 or earlier
Worked: 2.78c e92f235283 or later
Using python scripts, the method "user_remap" for image objects doesn't seem to work correctly anymore.
In the testfile I have 2 images. When I run the script to replace one image with the other, nothing happens in 2.79. The image is correctly replaced in 2.78c and both cubes are red (need to force redraw of viewport by zooming etc.)