Support qualified referencing for `ntpath.abspath()`

Feature or enhancement

Proposal:

from @eryksun (https://github.com/python/cpython/pull/117855#discussion_r1579025703):

Offhand I can't remember why normpath() gets called first. The fact that it removes an initial "." component is even more of a nuisance now. It prevents qualified referencing of files with certain DOS device names in the working directory such as "./con" versus unqualified "con". Support for the latter was added in Windows 11. For example:

>>> nt._getfullpathname('./con')
'C:\\Temp\\con'
>>> nt._getfullpathname('con')
'\\\\.\\con'
>>> os.path.abspath('./con')
'\\\\.\\con'

Calling normpath() first was always an issue for unambiguous references to file streams of single-letter filenames in the current directory. For example:

>>> nt._getfullpathname('./Z:spam')
'C:\\Temp\\Z:spam'
>>> os.path.abspath('./Z:spam')
'Z:\\spam'

Windows would beg to differ about the significance of a leading "." component, in these cases and others. Anyway, I thought this version could at least address the inconsistent behavior with embedded null characters, while still calling normpath() first.

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

• #117587
• #119826

Linked PRs

• gh-119849
• gh-126784

从 ntpath.abspath() 入口点开始，阅读 #117587 和 #119826 中链接的讨论，以及 PR #119849 和 #126784。复现 './con' 和 './Z:spam' 的 Windows 示例；完成的标准是限定引用保留其预期行为，且不会使现有的 abspath 处理发生回归。