[b84330808]

Type of Changes

	Type
✓	🐛 Bug fix

Description

In pylint-dev/pylint#10352, a pylint plugin with a FunctionDef transform that only returns its node makes pylint report missing-function-docstring on a method that overrides a method of a PEP 695 generic class, because the subclass loses its ancestors:

class Base[T]: ...
class Middle[T](Base[T]): ...
class Child(Middle[int]): ...

Child.ancestors() gives Middle, Base, object, but only Middle when such a transform is registered and Middle's base was inferred before (pylint does a lot of inference before the docstring checker runs).

What happens:

1. infer_typing_generic_class_pep695 parses a __class_getitem__ template each time a class with type parameters is inferred.
2. Parsing applies the registered transforms. TransformVisitor._transform treats any non-None return value as a replacement and calls _invalidate_cache(), which clears the global inference cache.
3. This happens in the middle of inferring Child's ancestors. Further down, Base[T] is inferred again while it is already on the inference path. Before, the cache answered that. Now it hits the recursion guard, InferenceError is raised, and ancestors() skips the base.

The fix builds the template with AstroidBuilder(..., apply_transforms=False), the same way brain_namedtuple_enum builds its fake enum classes during inference. The template is a fixed classmethod, and running user transforms on it was not useful anyway.

I first tried skipping _invalidate_cache() when a transform returns the same node it got. That fixes this case but breaks test_tuple_type, test_callable_type, test_namedtuple_advanced_inference and test_mro_with_factories, and three of pylint's typing functional tests: some brains change a node in place, return it, and rely on that invalidation. So I limited the fix to the brain.

The new test fails without the change. The rest of the astroid tests and pylint's functional tests (944) pass with it. 6 symlink and .pyz tests fail on my Windows machine with and without this change. The example from the issue no longer gets missing-function-docstring.

Closes pylint-dev/pylint#10352

I used Claude Code for this PR and reviewed the change and the results.