From b79df0b35861400f573e74d0305d7298c221e7ff Mon Sep 17 00:00:00 2001
From: Ian Wilson <ian.owings@gmail.com>
Date: Fri, 6 Sep 2013 16:25:34 -0500
Subject: [PATCH] adds fix for SingleObjectTemplateResponseMixin raising a
 TemplateDoesNotExist when it should have raised an ImproperlyConfigured.
 fixes 16502. by @ianawilson, @jambonrose

---
 django/views/generic/detail.py   | 48 ++++++++++++++++++--------------
 tests/generic_views/test_base.py | 12 ++++++++
 tests/generic_views/views.py     |  8 ++++++
 3 files changed, 47 insertions(+), 21 deletions(-)

diff --git a/django/views/generic/detail.py b/django/views/generic/detail.py
index 5ce8092c67..466954c03a 100644
--- a/django/views/generic/detail.py
+++ b/django/views/generic/detail.py
@@ -137,28 +137,34 @@ class SingleObjectTemplateResponseMixin(TemplateResponseMixin):
             # we just start with an empty list.
             names = []
 
-        # If self.template_name_field is set, grab the value of the field
-        # of that name from the object; this is the most specific template
-        # name, if given.
-        if self.object and self.template_name_field:
-            name = getattr(self.object, self.template_name_field, None)
-            if name:
-                names.insert(0, name)
+            # If self.template_name_field is set, grab the value of the field
+            # of that name from the object; this is the most specific template
+            # name, if given.
+            if self.object and self.template_name_field:
+                name = getattr(self.object, self.template_name_field, None)
+                if name:
+                    names.insert(0, name)
+
+            # The least-specific option is the default <app>/<model>_detail.html;
+            # only use this if the object in question is a model.
+            if isinstance(self.object, models.Model):
+                names.append("%s/%s%s.html" % (
+                    self.object._meta.app_label,
+                    self.object._meta.model_name,
+                    self.template_name_suffix
+                ))
+            elif hasattr(self, 'model') and self.model is not None and issubclass(self.model, models.Model):
+                names.append("%s/%s%s.html" % (
+                    self.model._meta.app_label,
+                    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
 
-        # The least-specific option is the default <app>/<model>_detail.html;
-        # only use this if the object in question is a model.
-        if isinstance(self.object, models.Model):
-            names.append("%s/%s%s.html" % (
-                self.object._meta.app_label,
-                self.object._meta.model_name,
-                self.template_name_suffix
-            ))
-        elif hasattr(self, 'model') and self.model is not None and issubclass(self.model, models.Model):
-            names.append("%s/%s%s.html" % (
-                self.model._meta.app_label,
-                self.model._meta.model_name,
-                self.template_name_suffix
-            ))
         return names
 
 
diff --git a/tests/generic_views/test_base.py b/tests/generic_views/test_base.py
index b1dd7a3040..bd354ee091 100644
--- a/tests/generic_views/test_base.py
+++ b/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)
diff --git a/tests/generic_views/views.py b/tests/generic_views/views.py
index f839b53753..aaff644a14 100644
--- a/tests/generic_views/views.py
+++ b/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/'