indexed colours lost when saving
Environment/Versions
- GIMP version: 2.10
- Package: from Pop OS official package manager (flatpak)
- Operating System: Linux Pop OS
Description of the bug
When applying a custom indexed palette of 256 colours to a image then when exporting it to .gif any unused colours are removed. There is no option to disable this behaviour except when loading the palette but then what was the point if it will just cut them when exporting.
Reproduction
Reproduction steps:
- open pixel art picture.
- change mode to indexed.
- crop a small part of the picture that does not use all the colours preferably a black patch.
- export to .gif format and close the image in gimp.
- load the .gif file you just exported and the colours will be reduced.
Expected result: should have retained the correct full colour palette.
Actual result: any unused colours were removed.
Additional information
I make games using gimp for the artwork and having inconsistencies in the palettes can effect the end result that is why I have reported this issue as I can not find any work around. I have not noticed this issue when exporting to any other formats just .gif images.