Fixed #18829 -- Fixed ModelChoiceIterator length

Thanks facundo.olano at gmail.com for the report and thikonom for
the initial patch.

2 files changed, 3 insertions, 1 deletions

diff --git a/django/forms/models.py b/django/forms/models.py
index 75d526d173..3905e9e902 100644
--- a/django/forms/models.py
+++ b/django/forms/models.py
@@ -917,7 +917,8 @@ class ModelChoiceIterator(object):
                 yield self.choice(obj)
 
     def __len__(self):
-        return len(self.queryset)
+        return len(self.queryset) +\
+                    (1 if self.field.empty_label is not None else 0)
 
     def choice(self, obj):
         return (self.field.prepare_value(obj), self.field.label_from_instance(obj))
diff --git a/tests/modeltests/model_forms/tests.py b/tests/modeltests/model_forms/tests.py
index efaf2981e1..f9ef61536c 100644
--- a/tests/modeltests/model_forms/tests.py
+++ b/tests/modeltests/model_forms/tests.py
@@ -989,6 +989,7 @@ class OldFormForXTests(TestCase):
             (c2.pk, "It's a test"),
             (c3.pk, 'Third'),
             (c4.pk, 'Fourth')])
+        self.assertEqual(5, len(f.choices))
         with self.assertRaises(ValidationError):
             f.clean('')
         with self.assertRaises(ValidationError):