Refs #15250 -- Removed an obsolete comment regarding MTI cascade deletion.

django/db/models/deletion.py

@@ -200,10 +200,6 @@ class Collector(object):
             concrete_model = model._meta.concrete_model
             for ptr in six.itervalues(concrete_model._meta.parents):
                 if ptr:
-                    # FIXME: This seems to be buggy and execute a query for each
-                    # parent object fetch. We have the parent data in the obj,
-                    # but we don't have a nice way to turn that data into parent
-                    # object instance.
                     parent_objs = [getattr(obj, ptr.name) for obj in new_objs]
                     self.collect(parent_objs, source=model,
                                  source_attr=ptr.remote_field.related_name,

tests/delete/tests.py

@@ -475,11 +475,7 @@ class FastDeleteTests(TestCase):
         c = Child.objects.create()
         p = Parent.objects.create()
         # 1 for self, 1 for parent
-        # However, this doesn't work as child.parent access creates a query,
-        # and this means we will be generating extra queries (a lot for large
-        # querysets). This is not a fast-delete problem.
-        # self.assertNumQueries(2, c.delete)
-        c.delete()
+        self.assertNumQueries(2, c.delete)
         self.assertFalse(Child.objects.exists())
         self.assertEqual(Parent.objects.count(), 1)
         self.assertEqual(Parent.objects.filter(pk=p.pk).count(), 1)