EnhancedRemapper.MMethod will NPE for (null, !null) constructor arguments

[TropheusJ]

Access is unconditionally queried from the IMethodInfo here, even though it's nullable.

[shartte]

Can you provide an actual jar this happens with?

[TropheusJ]

Minecraft 1.21.4, but I'm operating on it class-by-class in-memory.

Transformer transformer = new RenamingTransformer(ClassProvider.builder().build(), this.mappings, message -> {});
Transformer.ClassEntry entry = Transformer.ClassEntry.create(name + ".class", Transformer.Entry.STABLE_TIMESTAMP, bytes);
Transformer.ClassEntry processed = transformer.process(entry);

[sciwhiz12]

Just from reading the code, it seems this is possible if the EnhancedRemapper#computeClass method is called with a class name which has no classfile but has a mapping entry.

As a potential side-goal, all the methods and fields should be annotated with the proper nullability annotations (since we do compile-only depend on JetBrains annotations), to find and check against these kinds of nullability errors.