Django 5.2.2 incompatibly removed q from MediaType.params

[Anders Kaseorg]

​https://github.com/django/django/pull/19507#discussion_r2130422564

Between Django 5.2.1 and 5.2.2, the q entry was removed from the MediaType.params dict. Even though MediaType is not documented as a public API, it does have users (such as Zulip). This seems like an unnecessary breaking change, especially for a stable patch release. I was asked to file a ticket for this, so here it is.

[Natalia Bidart]

Hello Anders, thank you for creating this ticket. Accepting based on the PR conversation.

Regression in c075508b4de8edf9db553b409f8a8ed2f26ecead.

[nessita <124304+nessita@…>]

In cf5f36b:

Fixed #36446 -- Restored "q" in internal MediaType.params property.

The "q" key was removed while addressing ticket #36411. Despite
MediaType.params is undocumented and considered internal, it was used
in third-party projects (Zulip reported breakage), so this work restored
the q key in params.

Thanks Anders Kaseorg for the report.

Regression in c075508b4de8edf9db553b409f8a8ed2f26ecead.

[Natalia <124304+nessita@…>]

In cc50797:

[5.2.x] Fixed #36446 -- Restored "q" in internal MediaType.params property.

The "q" key was removed while addressing ticket #36411. Despite
MediaType.params is undocumented and considered internal, it was used
in third-party projects (Zulip reported breakage), so this work restored
the q key in params.

Thanks Anders Kaseorg for the report.

Regression in c075508b4de8edf9db553b409f8a8ed2f26ecead.

Backport of cf5f36bf903a2854f5e395149cee707115b83744 from main.