make InheritanceIterable inherit from ModelIterable instead of BaseIterable

AUTHORS.rst

@@ -15,6 +15,7 @@ Facundo Gaich <facugaich@gmail.com>
 Felipe Prenholato <philipe.rp@gmail.com>
 Filipe Ximenes <filipeximenes@gmail.com>
 Gregor Müllegger <gregor@muellegger.de>
+Hanley Hansen <hanleyhansen@gmail.com>
 ivirabyan
 James Oakley <jfunk@funktronics.ca>
 Jannis Leidel <jannis@leidel.info>

model_utils/managers.py

@@ -7,14 +7,14 @@ try:
     from django.db.models.query import BaseIterable, ModelIterable
 except ImportError:
     # Django 1.8 does not have iterable classes
-    BaseIterable = object
+    BaseIterable, ModelIterable = object, object
 from django.core.exceptions import ObjectDoesNotExist
 
 from django.db.models.constants import LOOKUP_SEP
 from django.utils.six import string_types
 
 
-class InheritanceIterable(BaseIterable):
+class InheritanceIterable(ModelIterable):
     def __iter__(self):
         queryset = self.queryset
         iter = ModelIterable(queryset)

tests/test_inheritance_iterable.py

@@ -0,0 +1,22 @@
+from __future__ import unicode_literals
+
+from unittest import skipIf
+
+import django
+from django.test import TestCase
+from django.db.models import Prefetch
+
+from tests.models import InheritanceManagerTestParent, InheritanceManagerTestChild1
+
+
+class InheritanceIterableTest(TestCase):
+    @skipIf(django.VERSION[:2] == (1, 10), "Django 1.10 expects ModelIterable not a subclass of it")
+    def test_prefetch(self):
+        qs = InheritanceManagerTestChild1.objects.all().prefetch_related(
+            Prefetch(
+                'normal_field',
+                queryset=InheritanceManagerTestParent.objects.all(),
+                to_attr='normal_field_prefetched'
+            )
+        )
+        self.assertEquals(qs.count(), 0)