gh-81790: support "UNC" device paths in `ntpath.splitdrive()` (GH-91882)

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Barney Gale 2022-06-10 16:59:55 +01:00 committed by GitHub
parent 53a8b17895
commit 2ba0fd5767
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5 changed files with 39 additions and 66 deletions

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@ -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")

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@ -172,17 +172,23 @@ def splitdrive(p):
sep = b'\\'
altsep = b'/'
colon = b':'
unc_prefix = b'\\\\?\\UNC'
else:
sep = '\\'
altsep = '/'
colon = ':'
unc_prefix = '\\\\?\\UNC'
normp = p.replace(altsep, sep)
if (normp[0:2] == sep*2) and (normp[2:3] != sep):
# is a UNC path:
# vvvvvvvvvvvvvvvvvvvv drive letter or UNC path
# \\machine\mountpoint\directory\etc\...
# directory ^^^^^^^^^^^^^^^
index = normp.find(sep, 2)
if normp[:8].upper().rstrip(sep) == unc_prefix:
start = 8
else:
start = 2
index = normp.find(sep, start)
if index == -1:
return p[:0], p
index2 = normp.find(sep, index + 1)

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@ -120,68 +120,18 @@ class _WindowsFlavour(_Flavour):
is_supported = (os.name == 'nt')
drive_letters = set('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ')
ext_namespace_prefix = '\\\\?\\'
reserved_names = (
{'CON', 'PRN', 'AUX', 'NUL', 'CONIN$', 'CONOUT$'} |
{'COM%s' % c for c in '123456789\xb9\xb2\xb3'} |
{'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):
first = part[0:1]
second = part[1:2]
if (second == sep and first == sep):
# XXX extended paths should also disable the collapsing of "."
# components (according to MSDN docs).
prefix, part = self._split_extended_path(part)
first = part[0:1]
second = part[1:2]
drv, rest = self.pathmod.splitdrive(part)
if drv[:1] == sep or rest[:1] == sep:
return drv, sep, rest.lstrip(sep)
else:
prefix = ''
third = part[2:3]
if (second == sep and first == sep and third != sep):
# is a UNC path:
# vvvvvvvvvvvvvvvvvvvvv root
# \\machine\mountpoint\directory\etc\...
# directory ^^^^^^^^^^^^^^
index = part.find(sep, 2)
if index != -1:
index2 = part.find(sep, index + 1)
# a UNC path can't have two slashes in a row
# (after the initial two)
if index2 != index + 1:
if index2 == -1:
index2 = len(part)
if prefix:
return prefix + part[1:index2], sep, part[index2+1:]
else:
return part[:index2], sep, part[index2+1:]
drv = root = ''
if second == ':' and first in self.drive_letters:
drv = part[:2]
part = part[2:]
first = third
if first == sep:
root = first
part = part.lstrip(sep)
return prefix + drv, root, part
return drv, '', rest
def casefold(self, s):
return s.lower()
@ -192,16 +142,6 @@ class _WindowsFlavour(_Flavour):
def compile_pattern(self, pattern):
return re.compile(fnmatch.translate(pattern), re.IGNORECASE).fullmatch
def _split_extended_path(self, s, ext_prefix=ext_namespace_prefix):
prefix = ''
if s.startswith(ext_prefix):
prefix = s[:4]
s = s[4:]
if s.startswith('UNC\\'):
prefix += s[:3]
s = '\\' + s[3:]
return prefix, s
def is_reserved(self, parts):
# NOTE: the rules for reserved names seem somewhat complicated
# (e.g. r"..\NUL" is reserved but not r"foo\NUL" if "foo" does not

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@ -117,6 +117,31 @@ class TestNtpath(NtpathTestCase):
# 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/")', ("", "//?/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("//?/VOLUME{00000000-0000-0000-0000-000000000000}/spam")',
('//?/VOLUME{00000000-0000-0000-0000-000000000000}', '/spam'))
tester('ntpath.splitdrive("//?/BootPartition/")', ("//?/BootPartition", "/"))
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\\")', ("", "\\\\?\\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("\\\\?\\VOLUME{00000000-0000-0000-0000-000000000000}\\spam")',
('\\\\?\\VOLUME{00000000-0000-0000-0000-000000000000}', '\\spam'))
tester('ntpath.splitdrive("\\\\?\\BootPartition\\")', ("\\\\?\\BootPartition", "\\"))
def test_split(self):
tester('ntpath.split("c:\\foo\\bar")', ('c:\\foo', 'bar'))

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@ -0,0 +1,2 @@
:func:`os.path.splitdrive` now understands DOS device paths with UNC
links (beginning ``\\?\UNC\``). Contributed by Barney Gale.