Test that cleanup() does not chmod the parent directory

Author: encukou

Lib/test/test_tempfile.py

@@ -2079,6 +2079,26 @@ def test_modes(self):
                     d.cleanup()
                 self.assertFalse(os.path.exists(d.name))
 
+    def test_parent_mode_preserved(self):
+        # Test that cleanup does not touch the parent directory,
+        # even if that prevents removal.
+        for mode in range(8):
+            mode <<= 6
+            with self.subTest(mode=format(mode, '03o')):
+                outer = self.do_create()
+                with outer:
+                    d = self.do_create(dir=outer.name, dirs=2, files=2)
+                    with d:
+                        os.chmod(outer.name, mode)
+                        orig_mode = os.stat(outer.name).st_mode
+                        try:
+                            d.cleanup()
+                        except PermissionError:
+                            pass
+                        self.assertEqual(os.stat(outer.name).st_mode, orig_mode)
+                        outer.cleanup()
+                self.assertFalse(os.path.exists(outer.name))
+
     def check_flags(self, flags):
         # skip the test if these flags are not supported (ex: FreeBSD 13)
         filename = os_helper.TESTFN