[1.5.x] Fixed #19262 -- Support cookie pickling in SimpleTemplateResponse

Refs #15863.
Backport of 4d817b3887 from master.

1 files changed, 1 insertions, 1 deletions

diff --git a/django/template/response.py b/django/template/response.py
index 2cb44d127d..3b3b41331a 100644
--- a/django/template/response.py
+++ b/django/template/response.py
@@ -40,7 +40,7 @@ class SimpleTemplateResponse(HttpResponse):
         rendered, and that the pickled state only includes rendered
         data, not the data used to construct the response.
         """
-        obj_dict = self.__dict__.copy()
+        obj_dict = super(SimpleTemplateResponse, self).__getstate__()
         if not self._is_rendered:
             raise ContentNotRenderedError('The response content must be '
                                           'rendered before it can be pickled.')