[New-bugs-announce] [issue46287] UNC path normalisation issues on Windows

[Steve Dower]

New submission from Steve Dower <steve.dower at python.org>:

Taken from https://github.com/python/cpython/pull/30362#issuecomment-1006840632

For Windows, should there be tests for invalid UNC paths such as "//", "//..", "//../..", "//../../..", "//server", "//server/..", and "//server/../.."? This will help to ensure that future changes never allow an invalid path to be normalized as a valid path.

Also, it's not a major problem that should prevent merging, but the way repeated slashes are handled prior to the second component of a UNC path is less than ideal:

>>> os.path.normpath('//spam///eggs')
'\\\\spam\\\\eggs'
>>> os.path.normpath('//spam///eggs/..')
'\\\\spam\\\\'
This case isn't a valid UNC share, since it's just "//spam", without a share component. However, the repeated slashes start the filepath part and should be reduced to a single backslash. That's what the GetFullPathNameW() call does in abspath():

>>> os.path.abspath('//spam///eggs')
'\\\\spam\\eggs'
>>> os.path.abspath('//spam///eggs/..')
'\\\\spam\\'

----------
components: Windows
messages: 409903
nosy: eryksun, paul.moore, steve.dower, tim.golden, zach.ware
priority: normal
severity: normal
stage: test needed
status: open
title: UNC path normalisation issues on Windows
type: behavior
versions: Python 3.11

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue46287>
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