File x.py is skiped if directory x exists #22160

Bug Report

The file 'x.py' is skipped if directory 'x' containing any python files exists.

To Reproduce

Create the following filestructure:

ddd/
  x.py
  x/
    y.py

content of x.py

def x(z: int):
    pass

no content needed in y.py

Expected Behavior

mypy shows error in x.py

Actual Behavior

No error is shown, x.py is not checked.

Your Environment

• Mypy version used: 2.4.0

• Mypy command-line flags: mypy ddd/ --strict

• Mypy configuration options from mypy.ini (and other config files):

• Python version used: 3.13