Local class warning falsely produced outside of Mixin class

[xpple]

Minecraft Development for IntelliJ plugin version

2025.1-1.8.9

IntelliJ version

#IU-251.23774.435

Operating System

Windows 11

Target platform

No response

Description of the bug

Commit 904a7b7 introduces a check for local classes inside Mixins, but it is not actually checked whether the local class is inside a Mixin class. That is, it will now trigger for all local classes. Relevant code: MixinInnerClassInspection.kt#L44-L51.

[moehreag]

I can reproduce this issue using 2025.2-1.8.9 with IC-2025.2.3 on Linux (arch).

Additionally there seem to be cases where (method-)local classes in mixin classes are allowed and work fine (example). I am not sure on the actual restrictions on the side of Mixin regarding local classes as the original report detailed an error.

[Earthcomputer]

That is confusing, I have no idea why your record class works.

[moehreag]

It also seems to work for non-record classes (example) but I can't explain the behavior any further either.