Fix union type conversion to path

git/refs/log.py

@@ -168,7 +168,7 @@ def __init__(self, filepath: Union[PathLike, None] = None) -> None:
  """Initialize this instance with an optional filepath, from which we will
  initialize our data. The path is also used to write changes back using the
  :meth:`write` method."""
- self._path = os.fspath(filepath)
+ self._path = None if filepath is None else os.fspath(filepath)
  if filepath is not None:
  self._read_from_file()
  # END handle filepath