clean of ModelMultipleChoiceField tries to return EmptyQuerySet

[pedro.celes123@…]

In the clean method of the class ModelMultipleChoiceField if the value of the field is not and the field is not required the method will return:

return self.queryset.none()
# In my version (1.6.5, final) this is on line 1180 of file django/forms/models.py

However in the release notes it is stated: "The django.db.models.query.EmptyQuerySet can’t be instantiated any more - it is only usable as a marker class for checking if none() has been called: isinstance(qs.none(), EmptyQuerySet)"

So if I have a form which contains a ModelMultipleChoiceField which is not required and no value is attached to it, in the validation process (more specifically in the clean of said field) the following error will be raised:

TypeError: EmptyQuerySet can't be instantiated

[Tim Graham]

I'm having a little trouble understanding how to trigger this error. Could you write a test case for Django's test suite that demonstrates it?

[pedro.celes123@…]

Sorry for the inconvenience, due to a monkey patch used in my company I was fooled to think the problem was with django. After more thorough tests we discovered the problem was with us.
Really sorry.

[Tim Graham]

No problem, thanks for following up.