Added test for ForeignObject.get_extra_descriptor_filter()

tests/foreign_object/models.py

@@ -146,7 +146,7 @@ class ActiveTranslationField(models.ForeignObject):
     def get_extra_restriction(self, where_class, alias, related_alias):
         return ColConstraint(alias, 'lang', get_language())
 
-    def get_extra_descriptor_filter(self):
+    def get_extra_descriptor_filter(self, instance):
         return {'lang': get_language()}
 
     def contribute_to_class(self, cls, name):

tests/foreign_object/tests.py

@@ -319,6 +319,9 @@ class MultiColumnFKTests(TestCase):
         at1_fi.save()
         at2_en = ArticleTranslation(article=a1, lang='en', title='Title', body='Lalalalala')
         at2_en.save()
+
+        self.assertEqual(Article.objects.get(pk=a1.pk).active_translation, at1_fi)
+
         with self.assertNumQueries(1):
             fetched = Article.objects.select_related('active_translation').get(
                 active_translation__title='Otsikko')