Fixed #16917 -- Don't try to use the model name for a ContentType's unicode…

Fixed #16917 -- Don't try to use the model name for a ContentType's unicode representation if the model no longer exists. Thanks Ivan Sagalaev for report and patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@16895 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/contenttypes/models.py

@@ -92,11 +92,11 @@ class ContentType(models.Model):
         #
         # We return self.name only when users have changed its value from the
         # initial verbose_name_raw and might rely on it.
-        meta = self.model_class()._meta
-        if self.name != meta.verbose_name_raw:
+        model = self.model_class()
+        if not model or self.name != model._meta.verbose_name_raw:
             return self.name
         else:
-            return force_unicode(meta.verbose_name)
+            return force_unicode(model._meta.verbose_name)
 
     def model_class(self):
         "Returns the Python model class for this type of content."

django/contrib/contenttypes/tests.py

@@ -109,3 +109,16 @@ class ContentTypesTests(TestCase):
         obj = FooWithoutUrl.objects.create(name="john")
 
         self.assertRaises(Http404, shortcut, request, user_ct.id, obj.id)
+
+    def test_missing_model(self):
+        """
+        Ensures that displaying content types in admin (or anywhere) doesn't
+        break on leftover content type records in the DB for which no model
+        is defined anymore.
+        """
+        ct = ContentType.objects.create(
+            name = 'Old model',
+            app_label = 'contenttypes',
+            model = 'OldModel',
+        )
+        self.assertEqual(unicode(ct), u'Old model')