gh-140774: Fix pathlib.Path.chmod not handling the Archive bit on Windows

Author: pareshjoshij

Lib/pathlib/__init__.py

@@ -1222,7 +1222,8 @@ def chmod(self, mode, *, follow_symlinks=True):
         """
         Change the permissions of the path, like os.chmod().
         """
-        os.chmod(self, mode, follow_symlinks=follow_symlinks)
+        # GH-127380: Force string path to ensure Windows archive bit handling works
+        os.chmod(str(self), mode, follow_symlinks=follow_symlinks)
 
     def lchmod(self, mode):
         """

Lib/test/test_pathlib/test_pathlib.py

@@ -3622,6 +3622,28 @@ def test_walk_symlink_location(self):
 class PosixPathTest(PathTest, PurePosixPathTest):
     cls = pathlib.PosixPath
 
+    def test_chmod_archive_bit_behavior(self):
+        base = self.cls(self.base)
+        filename = base / 'test_chmod_archive.txt'
+        filename.touch()
+        self.addCleanup(filename.unlink, missing_ok=True)
+
+        # Helper to check read-only status
+        def is_read_only(p):
+            return (p.stat().st_file_attributes & stat.FILE_ATTRIBUTE_READONLY) > 0
+        try:
+            # Case 1: Archive bit CLEARED, Read-Only SET
+            # We use attrib command to manipulate the Archive bit directly
+            subprocess.run(['attrib', '-a', '+r', str(filename)], check=True, shell=True)
+
+            # This line used to fail silently (bug #140774)
+            filename.chmod(stat.S_IWRITE | stat.S_IREAD)
+
+            self.assertFalse(is_read_only(filename),
+                "chmod failed to clear Read-Only when Archive bit was cleared")
+
+        except subprocess.CalledProcessError:
+            self.skipTest("attrib command failed or not available")
 
 @unittest.skipIf(os.name != 'nt', 'test requires a Windows-compatible system')
 class WindowsPathTest(PathTest, PureWindowsPathTest):