Failure to remap Mixin method reference if the class it is in is obfuscated, but it is an override of a non-obfuscated method.

[MildestToucan]

This issue was made apparent with the specific scenario of trying to target NonNullList#add(Object) in AbstractContainerMenu (MojMaps) with an injector.

Steps to reproduce

Specifically, this happened with Loom 1.14.7, on a mod project targeting Minecraft 1.21.10;
Whilst the Mixin worked just fine in a dev environment, it consistently crashed in production whenever targeting NonNullList#add. When dumping targets on failure was enabled:
The merged injector appeared as:

and the target method as:

Notice that the reference to the NonNullList field, named slots in MojMaps, was properly remapped, but how the NonNullField#add reference failed to be remapped.

The Fixes that worked

When using an expression to substitute add with a wildcard, the Mixin applied successfully. Upon LlamaLad prompting me to attempt reproducing the issue with the legacy AP enabled, the Mixin worked fine without needing to avoid targeting add directly.

A Gist of the post-fix buildscript and Mixin: https://gist.github.com/MildestToucan/06ae540b3c7c70e01ec2f4523ae76f27

This would indicate that without the AP, TR fails to remap when a Mixin tries to target a call to a method inherited from a non-obfuscated class, if in the context of it being called on an obfuscated class.

The Discord link for the discussion relating to this issue: https://discord.com/channels/507304429255393322/807617700734042122/1451510948740206592 and below.

A similar issue was brought up by dicedpixels after LlamaLad had prompted me to open this issue, linking me to https://discord.com/channels/507304429255393322/507982478276034570/1433480059267715184

where similar issues were experienced with trying to reference add in the context of MerchantOffers, an obfuscated class extending ArrayList.

I have insufficient knowledge to know how to solve this issue, but I was prompted by LlamaLad to open an issue here regarding it. I'm willing to provide additional details if needed.