Add docs, news, tests.

python · zooba · Jun 10, 2022 · Apr 24, 2022 · Apr 24, 2022 · Apr 24, 2022
commit 2da18baea29bfc9a3d91176666feb5f40d29dbb8
diff --git a/Doc/library/os.path.rst b/Doc/library/os.path.rst
@@ -469,7 +469,7 @@ the :mod:`glob` module.)
       ("c:", "/dir")
 
    If the path contains a UNC path, drive will contain the host name
-   and share, up to but not including the fourth separator::
+   and share::
 
       >>> splitdrive("//host/computer/dir")
       ("//host/computer", "/dir")

@@ -126,21 +126,6 @@ class _WindowsFlavour(_Flavour):
         {'LPT%s' % c for c in '123456789\xb9\xb2\xb3'}
         )
 
-    # Interesting findings about extended paths:
-    # * '\\?\c:\a' is an extended path, which bypasses normal Windows API
-    #   path processing. Thus relative paths are not resolved and slash is not
-    #   translated to backslash. It has the native NT path limit of 32767
-    #   characters, but a bit less after resolving device symbolic links,
-    #   such as '\??\C:' => '\Device\HarddiskVolume2'.
-    # * '\\?\c:/a' looks for a device named 'C:/a' because slash is a
-    #   regular name character in the object namespace.
-    # * '\\?\c:\foo/bar' is invalid because '/' is illegal in NT filesystems.
-    #   The only path separator at the filesystem level is backslash.
-    # * '//?/c:\a' and '//?/c:/a' are effectively equivalent to '\\.\c:\a' and
-    #   thus limited to MAX_PATH.
-    # * Prior to Windows 8, ANSI API bytes paths are limited to MAX_PATH,
-    #   even with the '\\?\' prefix.
-
     def splitroot(self, part, sep=sep):
         drv, rest = self.pathmod.splitdrive(part)
         if drv[:1] == sep or rest[:1] == sep:

diff --git a/Lib/test/test_ntpath.py b/Lib/test/test_ntpath.py
@@ -117,6 +117,22 @@ def test_splitdrive(self):
         # Issue #19911: UNC part containing U+0130
         self.assertEqual(ntpath.splitdrive('//conky/MOUNTPOİNT/foo/bar'),
                          ('//conky/MOUNTPOİNT', '/foo/bar'))
+        # gh-81790: support device namespace, including UNC drives.
+        tester('ntpath.splitdrive("//?/c:")', ("//?/c:", ""))
+        tester('ntpath.splitdrive("//?/c:/")', ("//?/c:", "/"))
+        tester('ntpath.splitdrive("//?/c:/dir")', ("//?/c:", "/dir"))
+        tester('ntpath.splitdrive("//?/UNC/")', ("", "//?/UNC/"))
+        tester('ntpath.splitdrive("//?/UNC/server/")', ("//?/UNC/server/", ""))
+        tester('ntpath.splitdrive("//?/UNC/server/share")', ("//?/UNC/server/share", ""))
+        tester('ntpath.splitdrive("//?/UNC/server/share/dir")', ("//?/UNC/server/share", "/dir"))
+        tester('ntpath.splitdrive("\\\\?\\c:")', ("\\\\?\\c:", ""))
+        tester('ntpath.splitdrive("\\\\?\\c:\\")', ("\\\\?\\c:", "\\"))
+        tester('ntpath.splitdrive("\\\\?\\c:\\dir")', ("\\\\?\\c:", "\\dir"))
+        tester('ntpath.splitdrive("\\\\?\\UNC\\")', ("", "\\\\?\\UNC\\"))
+        tester('ntpath.splitdrive("\\\\?\\UNC\\server\\")', ("\\\\?\\UNC\\server\\", ""))
+        tester('ntpath.splitdrive("\\\\?\\UNC\\server\\share")', ("\\\\?\\UNC\\server\\share", ""))
+        tester('ntpath.splitdrive("\\\\?\\UNC\\server\\share\\dir")',
+               ("\\\\?\\UNC\\server\\share", "\\dir"))
 
     def test_split(self):
         tester('ntpath.split("c:\\foo\\bar")', ('c:\\foo', 'bar'))

diff --git a/Misc/NEWS.d/next/Library/2022-04-24-22-26-45.gh-issue-81790.M5Rvpm.rst b/Misc/NEWS.d/next/Library/2022-04-24-22-26-45.gh-issue-81790.M5Rvpm.rst
@@ -0,0 +1,3 @@
+:func:`os.path.splitdrive` now understands DOS device paths (beginning
+``\\?\``), including UNC links (beginning ``\\?\UNC\``). Contributed by
+    Barney Gale.