Animation encoder transparency is broken

[slouken]

The easiest way to reproduce this is to run:
showanim -save butterfly.gif butterfly.ani

This example shows GIF encoding, but it looks like it's broken for all formats.

[slouken]

@LordOfXen, can you take a look at this?

Here's the butterfly animation I was using for testing:
https://sweezy-cursors.com/cursor/orange-butterfly-animated/

[LordOfXen]

Could you tell me what's exactly wrong with formats other than GIF?, I tried the butterfly GIF animation to create a WebP or PNG animation, and no transparency issues occurred.

[slouken]

I didn't verify that other formats were broken and I don't remember why I thought they would be affected. If you're not seeing any problems, we can ignore that feedback for now.

[LordOfXen]

Oh, alright, they seem to work. I performed the same tests as with GIF, and the results were always correct animation outputs.
(Quick note though, I only tested WebP and APNG, did not do the tests for AVIFS)