[3.10] gh-95789: update documentation RFC base URL

[JulianMaurin]

I did not find any way to override docutils default settings through sphinx so I had to create this configuration file.

Tested locally ✔️

The issue is also impacting python 3.7, 3.8 and 3.9. So I guess I've to create the exact same PR targeting another branch, may you confirm, please?

• Issue: RFC links are broken #95789

[bedevere-bot]

Most changes to Python require a NEWS entry.

Please add it using the blurb_it web app or the blurb command-line tool.

[cpython-cla-bot]

All commit authors signed the Contributor License Agreement.

[bedevere-bot]

Most changes to Python require a NEWS entry.

Please add it using the blurb_it web app or the blurb command-line tool.

[hugovk]

Rather than putting this in a new Doc/docutils.conf file, can we put rfc_base_url = 'https://datatracker.ietf.org/doc/html/' in the existing conf.py?

---

The issue is also impacting python 3.7, 3.8 and 3.9. So I guess I've to create the exact same PR targeting another branch, may you confirm, please?

As you noted at #95789 (comment), the redirects are fixed now on the IETF side, so it's less pressing to get this backported to the security-only branches. Let's ask 3.8/3.9 release manager @ambv.

[JulianMaurin]

Rather than putting this in a new Doc/docutils.conf file, can we put rfc_base_url = 'https://datatracker.ietf.org/doc/html/' in the existing conf.py?

That was my first intention. But actually conf.py is the configuration of sphinx.
In our case, the rfc_base_url is a docutils configuration (which is a dependency of sphinx).

I had a look at sphinx source code and the sphinx configuration is handled independently from the one of docutils.

[hugovk]

There's a rfc_base_url in both docutils and Sphinx.

We're overriding this setting in Sphinx:

    'rfc_base_url': 'https://datatracker.ietf.org/doc/html/',

https://github.com/sphinx-doc/sphinx/blob/f45dc5e1398f7850e23003cac200ad3433da2a78/sphinx/environment/__init__.py#L47

To test, I modified that line directly in Sphinx and rebuilt the docs, and it used that modified one.

[JulianMaurin]

@hugovk ,

Yes, it's exactly the link I refer in my last message.
I invite you to test, putting rfc_base_url in the conf.py. Rebuilding the documentation you will see that there is no impact.

(cf. https://www.sphinx-doc.org/en/master/usage/configuration.html)

[hugovk]

Ah yes, thanks!

Please could you prefix the title of this PR with "[3.10] " and add a news entry?

[hugovk]

Thank you!