Tarfile regression

Bug report

Bug description:

The function _get_filtered_attrs in tarfile.py references the special value os.path.ALLOW_MISSING. This is a problem because this value was only introduced in Python 3.14. However, the reference to this value has been backported to earlier supported Python versions. The result is that tarfile.py can throw an exception when being called from Python versions prior to 3.14.

  File "/usr/local/lib/python3.12/tarfile.py", line 845, in data_filter
    new_attrs = _get_filtered_attrs(member, dest_path, True)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/tarfile.py", line 770, in _get_filtered_attrs
    dest_path = os.path.realpath(dest_path, strict=os.path.ALLOW_MISSING)
                                                   ^^^^^^^^^^^^^^^^^^^^^
AttributeError: module 'posixpath' has no attribute 'ALLOW_MISSING'

In Python 3.12, the bug first appears in version 3.12.11.

In the Python 3.13 branch, the bug was introduced in 3.13.4, and persists in all subsequent versions.

In Python 3.11, it appears in all versions after and including 3.11.13

And in the Python 3.10 line, 3.10.18 is the first version where this value appears.

Personally, my symptom of this problem is that this bug prevents me from installing common libraries such as numpy because pip uses the tarfile library to unpack the download from PyPI.

CPython versions tested on:

3.12

Operating systems tested on:

Linux

從 tarfile.py 中的 _get_filtered_attrs 開始，然後在 3.14 之前的支援 Python 版本上重現已回報的 data_filter 失敗。確認 tarfile 操作不再因 os.path.ALLOW_MISSING 而引發 AttributeError，並確認已處理所回報的安裝情境。