bpo-46362: Ensure ntpath.abspath() uses the Windows API correctly (GH-30571)

This makes ntpath.abspath()/getpath_abspath() follow normpath(), since some WinAPIs such as PathCchSkipRoot() require backslashed paths.

1 files changed, 27 insertions, 0 deletions

diff --git a/Lib/test/test_embed.py b/Lib/test/test_embed.py
index dd43669..02bbe35 100644
--- a/Lib/test/test_embed.py
+++ b/Lib/test/test_embed.py
@@ -1404,6 +1404,33 @@ class InitConfigTests(EmbeddingTestsMixin, unittest.TestCase):
                                    api=API_COMPAT, env=env,
                                    ignore_stderr=True, cwd=tmpdir)
 
+    @unittest.skipUnless(MS_WINDOWS, 'specific to Windows')
+    def test_getpath_abspath_win32(self):
+        # Check _Py_abspath() is passed a backslashed path not to fall back to
+        # GetFullPathNameW() on startup, which (re-)normalizes the path overly.
+        # Currently, _Py_normpath() doesn't trim trailing dots and spaces.
+        CASES = [
+            ("C:/a. . .",  "C:\\a. . ."),
+            ("C:\\a. . .", "C:\\a. . ."),
+            ("\\\\?\\C:////a////b. . .", "\\\\?\\C:\\a\\b. . ."),
+            ("//a/b/c. . .", "\\\\a\\b\\c. . ."),
+            ("\\\\a\\b\\c. . .", "\\\\a\\b\\c. . ."),
+            ("a. . .", f"{os.getcwd()}\\a"),  # relpath gets fully normalized
+        ]
+        out, err = self.run_embedded_interpreter(
+            "test_init_initialize_config",
+            env=dict(PYTHONPATH=os.path.pathsep.join(c[0] for c in CASES))
+        )
+        self.assertEqual(err, "")
+        try:
+            out = json.loads(out)
+        except json.JSONDecodeError:
+            self.fail(f"fail to decode stdout: {out!r}")
+
+        results = out['config']["module_search_paths"]
+        for (_, expected), result in zip(CASES, results):
+            self.assertEqual(result, expected)
+
     def test_global_pathconfig(self):
         # Test C API functions getting the path configuration:
         #