Attempt to restore ntpath test

Author: ambv

Lib/test/test_ntpath.py

@@ -979,17 +979,40 @@ def test_realpath_permission(self):
         except AssertionError:
             raise unittest.SkipTest('the filesystem seems to lack support for short filenames')
 
-        # Deny the right to [S]YNCHRONIZE on the file to
-        # force nt._getfinalpathname to fail with ERROR_ACCESS_DENIED.
         p = subprocess.run(
-            ['icacls.exe', test_file, '/deny', '*S-1-5-32-545:(S)'],
-            creationflags=subprocess.DETACHED_PROCESS
+            ['whoami.exe', '/GROUPS'],
+            creationflags=subprocess.DETACHED_PROCESS,
+            capture_output=True,
         )
-
         if p.returncode:
+            raise unittest.SkipTest('cannot check group membership')
+
+        groups_output = p.stdout
+        groups = (
+            'S-1-5-32-544',  # Administrators
+            'S-1-5-32-545',  # Users
+        )
+
+        for group in groups:
+            if group.encode() not in groups_output:
+                continue
+
+            # Deny the right to [S]YNCHRONIZE on the file to
+            # force nt._getfinalpathname to fail with ERROR_ACCESS_DENIED.
+            p = subprocess.run(
+                ['icacls.exe', test_file, '/deny', f'*{group}:(S)'],
+                creationflags=subprocess.DETACHED_PROCESS
+            )
+            if p.returncode == 0:
+                break
+        else:
             raise unittest.SkipTest('failed to deny access to the test file')
 
         self.assertPathEqual(test_file, ntpath.realpath(test_file_short))
+        with self.assertRaises(OSError):
+            ntpath.realpath(test_file_short, strict=True)
+        with self.assertRaises(OSError):
+            ntpath.realpath(test_file_short, strict=ALLOW_MISSING)
 
     def test_expandvars(self):
         with os_helper.EnvironmentVarGuard() as env: