gh-42948: Fix shutil.move() on permission-restricted filesystems

Author: ashm-dev

Lib/shutil.py

@@ -443,8 +443,13 @@ def lookup(name):
     else:
         st = lookup("stat")(src, follow_symlinks=follow)
     mode = stat.S_IMODE(st.st_mode)
-    lookup("utime")(dst, ns=(st.st_atime_ns, st.st_mtime_ns),
-        follow_symlinks=follow)
+    try:
+        lookup("utime")(dst, ns=(st.st_atime_ns, st.st_mtime_ns),
+            follow_symlinks=follow)
+    except OSError as e:
+        # Ignore permission errors when setting file times (gh-42948).
+        if e.errno not in (errno.EPERM, errno.EACCES):
+            raise
     # We must copy extended attributes before the file is (potentially)
     # chmod()'ed read-only, otherwise setxattr() will error with -EACCES.
     _copyxattr(src, dst, follow_symlinks=follow)

Lib/test/test_shutil.py

@@ -1251,6 +1251,52 @@ def _chflags_raiser(path, flags, *, follow_symlinks=True):
         finally:
             os.chflags = old_chflags
 
+    def test_copystat_handles_utime_errors(self):
+        # gh-42948: copystat should ignore permission errors when setting times
+        tmpdir = self.mkdtemp()
+        file1 = os.path.join(tmpdir, 'file1')
+        file2 = os.path.join(tmpdir, 'file2')
+        create_file(file1, 'xxx')
+        create_file(file2, 'xxx')
+
+        def make_utime_raiser(err):
+            def _utime_raiser(path, times=None, *, ns=None, dir_fd=None,
+                              follow_symlinks=True):
+                ex = OSError()
+                ex.errno = err
+                raise ex
+            return _utime_raiser
+
+        for err in errno.EPERM, errno.EACCES:
+            with unittest.mock.patch('os.utime', side_effect=make_utime_raiser(err)):
+                shutil.copystat(file1, file2)
+
+        with unittest.mock.patch('os.utime', side_effect=make_utime_raiser(errno.EINVAL)):
+            self.assertRaises(OSError, shutil.copystat, file1, file2)
+
+    @mock_rename
+    def test_move_handles_utime_errors(self):
+        # gh-42948: move should succeed despite utime permission errors
+        src_dir = self.mkdtemp()
+        dst_dir = self.mkdtemp()
+        src_file = os.path.join(src_dir, 'file')
+        dst_file = os.path.join(dst_dir, 'file')
+        create_file(src_file, 'content')
+
+        def _utime_raiser(path, times=None, *, ns=None, dir_fd=None,
+                          follow_symlinks=True):
+            ex = OSError()
+            ex.errno = errno.EPERM
+            raise ex
+
+        with unittest.mock.patch('os.utime', side_effect=_utime_raiser):
+            result = shutil.move(src_file, dst_file)
+            self.assertEqual(result, dst_file)
+            self.assertTrue(os.path.exists(dst_file))
+            self.assertFalse(os.path.exists(src_file))
+            with open(dst_file) as f:
+                self.assertEqual(f.read(), 'content')
+
     ### shutil.copyxattr
 
     @os_helper.skip_unless_xattr

Misc/NEWS.d/next/Library/2025-11-18-07-50-00.gh-issue-42948.uT9xKl.rst

@@ -0,0 +1,3 @@
+:func:`shutil.copystat` now ignores permission errors when setting file
+times. This fixes :func:`shutil.move` failures on filesystems where the user
+has write access but is not the owner. Patch by Shamil Abdulaev.