adds fix for SingleObjectTemplateResponseMixin raising a TemplateDoesNotExist when it should have raised an ImproperlyConfigured. fixes 16502. by @ianawilson, @jambonrose

django/views/generic/detail.py

@@ -159,6 +159,12 @@ class SingleObjectTemplateResponseMixin(TemplateResponseMixin):
                     self.model._meta.model_name,
                     self.template_name_suffix
                 ))
+
+            # If we still haven't managed to find any template names, we should
+            # re-raise the ImproperlyConfigured to alert the user.
+            if not names:
+                raise
+
         return names
 
 

tests/generic_views/test_base.py

@@ -468,3 +468,15 @@ class UseMultipleObjectMixinTest(unittest.TestCase):
         # Overwrite the view's queryset with queryset from kwarg
         context = test_view.get_context_data(object_list=queryset)
         self.assertEqual(context['object_list'], queryset)
+
+
+class SingleObjectTemplateResponseMixinTest(unittest.TestCase):
+
+    def test_create_view_with_form_only(self):
+        """
+        We want to makes sure that if you use a template mixin, but forget the
+        template, it still tells you it's ImproperlyConfigured instead of
+        TemplateDoesNotExist.
+        """
+        view = views.TemplateResponseWithoutTemplate()
+        self.assertRaises(ImproperlyConfigured, view.get_template_names)

tests/generic_views/views.py

@@ -92,6 +92,14 @@ class NaiveAuthorCreate(generic.CreateView):
     fields = '__all__'
 
 
+class TemplateResponseWithoutTemplate(generic.detail.SingleObjectTemplateResponseMixin, generic.View):
+    # we don't define the usual template_name here
+
+    def __init__(self):
+        # Dummy object, but attr is required by get_template_name()
+        self.object = None
+
+
 class AuthorCreate(generic.CreateView):
     model = Author
     success_url = '/list/authors/'