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

从 tarfile.py 中的 _get_filtered_attrs 开始，然后在 3.14 之前的受支持 Python 版本上重现已报告的 data_filter 失败。验证 tarfile 操作不再因 os.path.ALLOW_MISSING 而引发 AttributeError，并确认已处理所报告的安装场景。