Bug report

Bug description:

The error code was introduced by a security fix (at libexpat/libexpat@51c7019) but the XML_StopParser C-API is not exposed through CPython yet so it should not be possible to encounter such error. In particular, exposing the error code can be considered a feature or postpone until #59979 is resolved.

CPython versions tested on:

3.9, 3.10, 3.11, 3.12, 3.13, 3.14, CPython main branch

Operating systems tested on:

Linux, macOS, Windows, Other

Linked PRs

• gh-126624: Expose error code XML_ERROR_NOT_STARTED of Expat >=2.6.4 #126625