Description

barneygale

opened on Apr 17, 2023

Issue body actions

Low priority issue, follow-up from #78079.

On Windows, os.path.splitroot() produces incorrect results for all of the following paths:

>>> from ntpath import splitroot
>>> splitroot('//./Global/Global/UNC')
('//./Global', '/', 'Global/UNC')
>>> splitroot('//./Global/Z:/')
('//./Global', '/', 'Z:/')
>>> splitroot('//?/Global/Z:/')
('//?/Global', '/', 'Z:/')
>>> splitroot('//./Global/UNC')
('//./Global', '/', 'UNC')
>>> splitroot('//?/Global/UNC/server/share/dir')
('//?/Global', '/', 'UNC/server/share/dir')
>>> splitroot('//?/GLOBALROOT/ContainerMappedDirectories/93AA221C-4061-460F-8C4E-A2EAC1BF3324')
('//?/GLOBALROOT', '/', 'ContainerMappedDirectories/93AA221C-4061-460F-8C4E-A2EAC1BF3324')
>>> splitroot('//?/GLOBALROOT/Device/LanManRedirector/abc/xyz')
('//?/GLOBALROOT', '/', 'Device/LanManRedirector/abc/xyz')
>>> splitroot('//?/GLOBALROOT/Device/Mup/abc/xyz')
('//?/GLOBALROOT', '/', 'Device/Mup/abc/xyz')
>>> splitroot('//?/GLOBALROOT/Device/WebDavRedirector/abc/xyz')
('//?/GLOBALROOT', '/', 'Device/WebDavRedirector/abc/xyz')
>>> splitroot('//?/GLOBALROOT/DosDevices/UNC/abc/xyz')
('//?/GLOBALROOT', '/', 'DosDevices/UNC/abc/xyz')
>>> splitroot('//?/GLOBALROOT/??/UNC/abc/xyz')
('//?/GLOBALROOT', '/', '??/UNC/abc/xyz')

Activity

1. barneygale

   added

   type-bugAn unexpected behavior, bug, or errorAn unexpected behavior, bug, or error

   3.12only security fixesonly security fixes

   on Apr 17, 2023
2. eryksun commented on Apr 17, 2023

   

   eryksun

   on Apr 17, 2023

   Contributor

   More actions

   The "Global" qualifier would be consumed as part of the "\\.\" or "\\?\" device prefix. Using "Global" ensures that only system device names are found, bypassing local device names created in the current logon session via WinAPI DefineDosDeviceW() or NTAPI NtCreateSymbolicLinkObject(). Repeated "Global" qualifiers don't have to be supported.

   "GlobalRoot" can be handled like the "UNC" device, by consuming up to two subsequent components, e.g "\\.\GlobalRoot\Device\HarddiskVolume2". An exception could be made to consume up to two more components if the path is on the multiple UNC device (MUP), e.g. "\\?\GlobalRoot\Device\Mup\server\share". Such a path might me returned by os.readlink() if the symlink is absolute (no relative flag) and directly targets "\Device\Mup" instead of "\??\UNC". Or maybe a script is manipulating NT paths from GetFinalPathNameByHandleW(), for example:

   >>> h = CreateFile('//localhost/C$/Windows/py.exe', 0, 0, None, 3, 0, None)
   >>> p = GetFinalPathNameByHandle(h, VOLUME_NAME_NT)
   >>> p = '\\\\?\\GlobalRoot' + p
   >>> p
   '\\\\?\\GlobalRoot\\Device\\Mup\\localhost\\C$\\Windows\\py.exe'
   >>> h2 = CreateFile(p, 0, 0, None, 3, 0, None)
   >>> GetFinalPathNameByHandle(h2, VOLUME_NAME_DOS)
   '\\\\?\\UNC\\localhost\\C$\\Windows\\py.exe'

   Reacted by Barney Gale
3. eryksun

   added

   OS-windows

   3.13only security fixesonly security fixes

   on Apr 17, 2023
4. serhiy-storchaka

   added this to OS issues 💻on Jul 3, 2026
5. github-project-automation

   moved this to Todo in OS issues 💻on Jul 3, 2026

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