I made a compatibility test suite

[ali1234]

See https://xcf.zerostem.io/

This tool uses gimp scripting to generate xcf files with various combinations of layer blending. It exports each one as a png with gimp, gimpformats, layeredimage, and xcftools and compares the results. In gimpformats the conversion is done like this:

img = GimpDocument(...)
img.image.save(...)

Then it compares the png files. If any channel value differs by more than 8 then the test fails.

Of 648 tests, 550 failed.

[FredHappyface]

Cheers for the issue. Unfortunately I do not have the bandwidth to address the test failures per #1.

Affected users can do one of the following:

• Work around these by using simple layers etc
• Consider contributing to the project to improve the correctness of the compositor
• Consider using alternative software that meets their needs
• Consider saving in ORA or some more supported format