Django multipart parser creates mutable QueryDict

[k_bx]

When you send multipart request (which, unfortunately, is sent every time your testclient does POST-request https://code.djangoproject.com/ticket/18552 ), your view will get request.POST to be QueryDict with request.POST._mutable == True.

This caused me to write test that passes (sends POST-request and modifies request.POST in view), but production that fails.

[Luke Plant]

I haven't tested, but it sounds plausible.

[fred]

I can confirm the following behavior in 1.7.dev20130628193320, using the following view:

from django.views.decorators.csrf import csrf_exempt
from django.views.generic import View
from django.http import HttpResponse


class IndexView(View):
    def post(self, request):                                                                                                                                                                                
        return HttpResponse(bool(request.POST._mutable))

    @csrf_exempt
    def dispatch(self, *args, **kwargs):
        return super(IndexView, self).dispatch(*args, **kwargs)

The behavior is as follows:

• When this view is called with a POST of type application/x-www-form-urlencoded, it returns "False" (the POST is mutable).
• When this view is called with a POST of type multipart/form-data POST, it returns "True".
• Likewise, when calling the view through self.client.post('/view'), it returns "True". This confirms that the bug may lead to code that passes tests and fails in production.

I'd like to further look into this issue.

[Claude Paroz]

Duplicate of #17235