pythonGH-125413: Fix stale metadata from pathlib.Path.copy() and move() (python#130424)

In `pathlib.Path.copy()` and `move()`, return a fresh `Path` object with an
unpopulated `info` attribute, rather than a `Path` object with information
recorded *prior* to the path's creation.

Author: barneygale

Lib/pathlib/_abc.py

@@ -353,7 +353,8 @@ def copy(self, target, follow_symlinks=True, dirs_exist_ok=False,
             create = target._copy_writer._create
         except AttributeError:
             raise TypeError(f"Target is not writable: {target}") from None
-        return create(self, follow_symlinks, dirs_exist_ok, preserve_metadata)
+        create(self, follow_symlinks, dirs_exist_ok, preserve_metadata)
+        return target.joinpath()  # Empty join to ensure fresh metadata.
 
     def copy_into(self, target_dir, *, follow_symlinks=True,
                   dirs_exist_ok=False, preserve_metadata=False):

Lib/pathlib/_local.py

@@ -1098,7 +1098,8 @@ def copy(self, target, follow_symlinks=True, dirs_exist_ok=False,
             create = target._copy_writer._create
         except AttributeError:
             raise TypeError(f"Target is not writable: {target}") from None
-        return create(self, follow_symlinks, dirs_exist_ok, preserve_metadata)
+        create(self, follow_symlinks, dirs_exist_ok, preserve_metadata)
+        return target.joinpath()  # Empty join to ensure fresh metadata.
 
     def copy_into(self, target_dir, *, follow_symlinks=True,
                   dirs_exist_ok=False, preserve_metadata=False):
@@ -1128,10 +1129,12 @@ def move(self, target):
         else:
             ensure_different_files(self, target)
             try:
-                return self.replace(target)
+                os.replace(self, target)
             except OSError as err:
                 if err.errno != EXDEV:
                     raise
+            else:
+                return target.joinpath()  # Empty join to ensure fresh metadata.
         # Fall back to copy+delete.
         target = self.copy(target, follow_symlinks=False, preserve_metadata=True)
         self._delete()

Lib/test/test_pathlib/test_pathlib_abc.py

@@ -1391,17 +1391,17 @@ def test_copy_file(self):
         target = base / 'copyA'
         result = source.copy(target)
         self.assertEqual(result, target)
-        self.assertTrue(target.exists())
-        self.assertEqual(source.read_text(), target.read_text())
+        self.assertTrue(result.info.exists())
+        self.assertEqual(source.read_text(), result.read_text())
 
     def test_copy_file_to_existing_file(self):
         base = self.cls(self.base)
         source = base / 'fileA'
         target = base / 'dirB' / 'fileB'
         result = source.copy(target)
         self.assertEqual(result, target)
-        self.assertTrue(target.exists())
-        self.assertEqual(source.read_text(), target.read_text())
+        self.assertTrue(result.info.exists())
+        self.assertEqual(source.read_text(), result.read_text())
 
     def test_copy_file_to_existing_directory(self):
         base = self.cls(self.base)
@@ -1416,8 +1416,8 @@ def test_copy_file_empty(self):
         source.write_bytes(b'')
         result = source.copy(target)
         self.assertEqual(result, target)
-        self.assertTrue(target.exists())
-        self.assertEqual(target.read_bytes(), b'')
+        self.assertTrue(result.info.exists())
+        self.assertEqual(result.read_bytes(), b'')
 
     def test_copy_file_to_itself(self):
         base = self.cls(self.base)
@@ -1432,13 +1432,13 @@ def test_copy_dir_simple(self):
         target = base / 'copyC'
         result = source.copy(target)
         self.assertEqual(result, target)
-        self.assertTrue(target.is_dir())
-        self.assertTrue(target.joinpath('dirD').is_dir())
-        self.assertTrue(target.joinpath('dirD', 'fileD').is_file())
-        self.assertEqual(target.joinpath('dirD', 'fileD').read_text(),
+        self.assertTrue(result.info.is_dir())
+        self.assertTrue(result.joinpath('dirD').info.is_dir())
+        self.assertTrue(result.joinpath('dirD', 'fileD').info.is_file())
+        self.assertEqual(result.joinpath('dirD', 'fileD').read_text(),
                          "this is file D\n")
-        self.assertTrue(target.joinpath('fileC').is_file())
-        self.assertTrue(target.joinpath('fileC').read_text(),
+        self.assertTrue(result.joinpath('fileC').info.is_file())
+        self.assertTrue(result.joinpath('fileC').read_text(),
                         "this is file C\n")
 
     def test_copy_dir_complex(self, follow_symlinks=True):
@@ -1462,7 +1462,7 @@ def ordered_walk(path):
 
         # Compare the source and target trees
         source_walk = ordered_walk(source)
-        target_walk = ordered_walk(target)
+        target_walk = ordered_walk(result)
         for source_item, target_item in zip(source_walk, target_walk, strict=True):
             self.assertEqual(source_item[0].parts[len(source.parts):],
                              target_item[0].parts[len(target.parts):])  # dirpath
@@ -1472,12 +1472,12 @@ def ordered_walk(path):
             for filename in source_item[2]:
                 source_file = source_item[0].joinpath(filename)
                 target_file = target_item[0].joinpath(filename)
-                if follow_symlinks or not source_file.is_symlink():
+                if follow_symlinks or not source_file.info.is_symlink():
                     # Regular file.
                     self.assertEqual(source_file.read_bytes(), target_file.read_bytes())
-                elif source_file.is_dir():
+                elif source_file.info.is_dir():
                     # Symlink to directory.
-                    self.assertTrue(target_file.is_dir())
+                    self.assertTrue(target_file.info.is_dir())
                     self.assertEqual(source_file.readlink(), target_file.readlink())
                 else:
                     # Symlink to file.
@@ -1503,13 +1503,13 @@ def test_copy_dir_to_existing_directory_dirs_exist_ok(self):
         target.joinpath('dirD').mkdir()
         result = source.copy(target, dirs_exist_ok=True)
         self.assertEqual(result, target)
-        self.assertTrue(target.is_dir())
-        self.assertTrue(target.joinpath('dirD').is_dir())
-        self.assertTrue(target.joinpath('dirD', 'fileD').is_file())
-        self.assertEqual(target.joinpath('dirD', 'fileD').read_text(),
+        self.assertTrue(result.info.is_dir())
+        self.assertTrue(result.joinpath('dirD').info.is_dir())
+        self.assertTrue(result.joinpath('dirD', 'fileD').info.is_file())
+        self.assertEqual(result.joinpath('dirD', 'fileD').read_text(),
                          "this is file D\n")
-        self.assertTrue(target.joinpath('fileC').is_file())
-        self.assertTrue(target.joinpath('fileC').read_text(),
+        self.assertTrue(result.joinpath('fileC').info.is_file())
+        self.assertTrue(result.joinpath('fileC').read_text(),
                         "this is file C\n")
 
     def test_copy_dir_to_itself(self):
@@ -1524,15 +1524,15 @@ def test_copy_dir_into_itself(self):
         target = base / 'dirC' / 'dirD' / 'copyC'
         self.assertRaises(OSError, source.copy, target)
         self.assertRaises(OSError, source.copy, target, follow_symlinks=False)
-        self.assertFalse(target.exists())
+        self.assertFalse(target.info.exists())
 
     def test_copy_into(self):
         base = self.cls(self.base)
         source = base / 'fileA'
         target_dir = base / 'dirA'
         result = source.copy_into(target_dir)
         self.assertEqual(result, target_dir / 'fileA')
-        self.assertTrue(result.exists())
+        self.assertTrue(result.info.exists())
         self.assertEqual(source.read_text(), result.read_text())
 
     def test_copy_into_empty_name(self):

Misc/NEWS.d/next/Library/2025-02-21-21-50-21.gh-issue-125413.DEAD0L.rst

@@ -0,0 +1,2 @@
+Ensure the path returned from :meth:`pathlib.Path.copy` or
+:meth:`~pathlib.Path.move` has fresh :attr:`~pathlib.Path.info`.