Handle malformed release versions in docs versions view

[adityagiri3600]

Description

• Skip malformed release versions in DocsByVersionView when a release name does not include at least major.minor parts.
• Add a regression test to ensure /doc/versions/ still returns HTTP 200 when such a release exists.

Closes

[hugovk]

Is this about https://www.python.org/doc/versions/ ?

What exactly is malformed?

[adityagiri3600]

Yes.

By malformed I mean an incomplete release version that still matches the current regex like Python 4 matches Python ([\d.]+), but it doesn’t include at least major.minor. So full_version.split(".") has only one element, and the previous code accessed version_parts[1], which can raise IndexError and break the page.

If you prefer not to accept major only strings at all, I can update this to tighten parsing instead like require X.Y or X.Y.Z via a stricter regex instead of IndexError.

[hugovk]

I don't think this is needed, we'll never have a simple Python X release.

Python releases (with docs) are always X.Y.Z, and in the past we've had X.Y (the last was in 2011).

(Pre-releases can have a1, b1, rc1 suffixes, but they don't have docs.)

[adityagiri3600]

That makes sense, I appreciate this review. I'll close this PR.