[3.11] GH-88013: Fix TypeError raised by ntpath.realpath in some cases (GH-102813)

Lib/ntpath.py

@@ -644,7 +644,7 @@ def _getfinalpathname_nonstrict(path):
 
  # Non-strict algorithm is to find as much of the target directory
  # as we can and join the rest.
- tail = ''
+ tail = path[:0]
  while path:
  try:
  path = _getfinalpathname(path)

Lib/test/test_ntpath.py

@@ -1,5 +1,6 @@
 import ntpath
 import os
+import string
 import sys
 import unittest
 import warnings
@@ -321,6 +322,16 @@ def test_realpath_basic(self):
  self.assertPathEqual(ntpath.realpath(os.fsencode(ABSTFN + "1")),
  os.fsencode(ABSTFN))
 
+ # gh-88013: call ntpath.realpath with binary drive name may raise a
+ # TypeError. The drive should not exist to reproduce the bug.
+ for c in string.ascii_uppercase:
+ d = f"{c}:\\"
+ if not ntpath.exists(d):
+ break
+ else:
+ raise OSError("No free drive letters available")
+ self.assertEqual(ntpath.realpath(d), d)
+
  @os_helper.skip_unless_symlink
  @unittest.skipUnless(HAVE_GETFINALPATHNAME, 'need _getfinalpathname')
  def test_realpath_strict(self):

Misc/NEWS.d/next/Windows/2023-03-18-21-38-00.gh-issue-88013.Z3loxC.rst

@@ -0,0 +1,2 @@
+Fixed a bug where :exc:`TypeError` was raised when calling
+:func:`ntpath.realpath` with a bytes parameter in some cases.