Commit 7cca8d56 authored by Anssi Kääriäinen's avatar Anssi Kääriäinen
Browse files

Fixed related model lookup regression 

It has been possible to use models of wrong type in related field
lookups. For example pigs__in=[a_duck] has worked. Changes to
ForeignObject broke that.

It might be a good idea to restrict the model types usable in lookups.
This should be done intentionally, not accidentally and without any
consideration for deprecation path.
parent 31fadc12

django/db/models/fields/related.py

+1 −1
Original line number Diff line number Diff line
@@ -1060,7 +1060,7 @@ class ForeignObject(RelatedField): 
                value_list = []

                for source in sources:

                    # Account for one-to-one relations when sent a different model

                    while not isinstance(value, source.model):

                    while not isinstance(value, source.model) and source.rel:

                        source = source.rel.to._meta.get_field(source.rel.field_name)

                    value_list.append(getattr(value, source.attname))

                return tuple(value_list)

tests/queries/tests.py

+16 −0
Original line number Diff line number Diff line
@@ -2939,3 +2939,19 @@ class Ticket20788Tests(TestCase): 
            chapter__paragraph__page=page)

        self.assertQuerysetEqual(

            sentences_not_in_pub, [book2], lambda x: x)



class RelatedLookupTypeTests(TestCase):

    def test_wrong_type_lookup(self):

        oa = ObjectA.objects.create(name="oa")

        wrong_type = Order.objects.create(id=oa.pk)

        ob = ObjectB.objects.create(name="ob", objecta=oa, num=1)

        # Currently Django doesn't care if the object is of correct

        # type, it will just use the objecta's related fields attribute

        # (id) for model lookup. Making things more restrictive could

        # be a good idea...

        self.assertQuerysetEqual(

            ObjectB.objects.filter(objecta=wrong_type),

            [ob], lambda x: x)

        self.assertQuerysetEqual(

            ObjectB.objects.filter(objecta__in=[wrong_type]),

            [ob], lambda x: x)