Overlay engine rendered the editor background incorrectly when no image
is present. It used to render an alpha checker background indicating
that an image was present. The cause for this was that the in front
depth texture was attached, but isn't used at all.
The second change is that the image prepass should only be drawn when
there is an image present in the image editor other wise external the
prepass would alter the depth texture indicating that there is an image
present.
Pull Request: https://projects.blender.org/blender/blender/pulls/132847
6bcf34668a