Fixed #24829 -- Allowed use of TemplateResponse in view error handlers.

tests/handlers/tests_custom_error_handlers.py

@@ -0,0 +1,30 @@
+from django.conf.urls import url
+from django.core.exceptions import PermissionDenied
+from django.template.response import TemplateResponse
+from django.test import SimpleTestCase, override_settings
+
+
+def template_response_error_handler(request, exception=None):
+    return TemplateResponse(request, 'test_handler.html', status=403)
+
+
+def permission_denied_view(request):
+    raise PermissionDenied
+
+
+urlpatterns = [
+    url(r'^$', permission_denied_view),
+]
+
+handler403 = template_response_error_handler
+
+
+@override_settings(ROOT_URLCONF='handlers.tests_custom_error_handlers')
+class CustomErrorHandlerTests(SimpleTestCase):
+
+    def test_handler_renders_template_response(self):
+        """
+        BaseHandler should render TemplateResponse if necessary.
+        """
+        response = self.client.get('/')
+        self.assertContains(response, 'Error handler content', status_code=403)