HttpResponseRedirect fail on reverse_lazy with Python 3.2

[Natim87]

Let's have an example :

In a delete view, you need to do that to fix the problem:

class TaskDeleteView(DeleteView):
    model = Task
    success_url = reverse_lazy('task:list')

    def get_success_url(self):
        return str(self.success_url)

If you don't define get_success_url and return the str() you get and attribute error proxy doesn't have a decode attribute.

[Claude Paroz]

Mmmmh... it's not the first time I'm confronted with issues related to the new Python 3 urlparse implementation and its isinstance dance :-(

The problem cannot be triggered in ModelFormMixin-based views because the lazy reverse is resolved by an interpolation (self.success_url % self.object.__dict__). However, it is a problem in FormMixin version of get_success_url, where we probably will have to force the lazy evaluation.

[Claude Paroz]

Force reverse_lazy evaluation

[Claude Paroz]

I was a bit surprised to not find existing FormView tests. Maybe I missed them?

[Claude Paroz <claude@…>]

In 795ac7deda64e67a059b489f8684bb440ca7f7ad:

Fixed #19378 -- Ensured get_success_url returns a non-lazy URL

[Claude Paroz <claude@…>]

In 7fea7cf5d74a488f0c81b76cb7dc7fa74a86569c:

[1.5.x] Fixed #19378 -- Ensured get_success_url returns a non-lazy URL

Backport of 795ac7deda from master.