Django message framework add_message() should prefer ducktyping over isinstance

[Raffaele Salmaso]

Original ticket https://code.djangoproject.com/ticket/21412

django.contrib.messages.add_message check for an HttpRequest object instance, and cannot work as-is with django-rest-framework request wrapper, requiring to use the wrapped object directly

messages.add_message(request._request, ...)

add_message() should not use isinstance check.

[Josh Smeaton]

Funny, we actually ran into this at work yesterday.

[Raffaele Salmaso]

PR => ​https://github.com/django/django/pull/7794

I've update original test to be sure that the 'django.contrib.messages.middleware.MessageMiddleware' is not in settings.MIDDLEWARE,
and added a custom request object

[Raffaele Salmaso]

Updated check so can be used a custom middleware (if really it is needed).

[Tim Graham]

Looks like the patch was revised after "Ready for checkin" was set. I've left some comments for improvement.

[Raffaele Salmaso]

Update the PR (mostly rewritten).
Now it is similar to original behaviour.

[Raffaele Salmaso]

Update PR as per comments.

[Tim Graham <timograham@…>]

In ed8c0c94:

Fixed #27688 -- Made messages' add_message() request check use ducktyping.