Cleanup duplication of HTTP header parsing in utils.http and multipart parser.

[Carlton Gibson]

PY311 deprecated the cgi module.

We removed usage of that in ​PR 15679.

There's similar logic already in place in multipartparser.py, but header parameters are parsed slightly differently, and the return types of the helper functions used don't match exactly. (​Comment on the PR linking to the code locations.)

Nonetheless it looks like we should be able to combine the two functions to have a single parsing routine.

[Mariusz Felisiak]

It looks that the only difference between _parseparam() and django.http.multipartparser._parse_header_params() is that it works on strings (instead of bytes) and that it contains ​https://github.com/python/cpython/commit/1ef0c0349e8fdb5415e21231cb42edbf232b742a (which is desired in both places).

[Carlton Gibson]

+1 Yes. (And there's the list vs scalar thing... but that's just needing to sit and think it through clearly.) — Ideal would be to unify on a single version in utils and use in both places.

[Kapil Bansal]

Hi,
I want to give this issue a try. Although I am not sure how to run and check what these functions are doing?
Would it be like creating a new django project and tests from where this function is called? Or something else?

[Carlton Gibson]

Hi Kapil.

There's already some coverage, so making the change ensuring the existing tests pass would be a start.

On implementation, you may find you need to adjust tests, or add new ones. That's OK.

If we need extra tests after that, they can be suggested on review.

The ​Submitting patches guide should help you on your next steps.

Thanks!

[Carlton Gibson]

​PR

[Mehrdad Moradizadeh]

I have made a ​PR for this issue.

[Mariusz Felisiak <felisiak.mariusz@…>]

In 93cedc8:

Refs #33697 -- Fixed multipart parsing of headers with double quotes and semicolons.

See ​https://github.com/python/cpython/commit/1ef0c0349e8fdb5415e21231cb42edbf232b742a

[Mariusz Felisiak <felisiak.mariusz@…>]

In 2f974e3:

[4.1.x] Refs #33697 -- Fixed multipart parsing of headers with double quotes and semicolons.

See ​https://github.com/python/cpython/commit/1ef0c0349e8fdb5415e21231cb42edbf232b742a

Backport of 93cedc82f29076c824d476354527af1150888e4f from main

[Mariusz Felisiak <felisiak.mariusz@…>]

In 49b470b9:

Refs #33697 -- Made MultiPartParser use django.utils.http.parse_header_parameters() for parsing Content-Type header.

[Mariusz Felisiak]

​New PR

[Mariusz Felisiak <felisiak.mariusz@…>]

In d6e0c7c3:

Refs #33697 -- Made MediaType use django.utils.http.parse_header_parameters().

[Mariusz Felisiak <felisiak.mariusz@…>]

In d4d54275:

Refs #33697 -- Used django.utils.http.parse_header_parameters() for parsing boundary streams.

This also removes unused parse_header() and _parse_header_params()
helpers in django.http.multipartparser.

[GitHub <noreply@…>]

In 154dd1c:

Refs #33697 -- Added backward incompatibility note about removing multipartparser.parse_header().