How to reproduce:
- Have image editor and GPU compositor backdrop enabled and showing the same image
- In image editor, apply inver image colors operator
- Notice how image editor gets updated but compositor backdrop doesn't
Fixes backdrop updates for GPU compositor for the following operators:
- Image -> Invert -> Invert image colors
- Image -> Invert -> Invert red channel
- Image -> Invert -> Invert green channel
- Image -> Invert -> Invert blue channel
- Image -> Invert -> Invert alpha channel
Pull Request: https://projects.blender.org/blender/blender/pulls/119820
e1a0b6cd9e