Ticket #23070: 23070.diff

django/views/debug.py

@@ -13 +13 @@
 from django.template.defaultfilters import force_escape, pprint
 from django.utils.datastructures import MultiValueDict
 from django.utils.html import escape
-from django.utils.encoding import force_bytes, smart_text
+from django.utils.encoding import force_bytes, force_text, smart_text
 from django.utils.module_loading import import_string
 from django.utils import six
 
@@ -50 +50 @@
         cleansed = value
 
     if callable(cleansed):
-        cleansed.do_not_call_in_templates = True
+        # For fixing #21345 and #23070
+        cleansed = force_text(cleansed)
 
     return cleansed
 

tests/view_tests/tests/test_debug.py

@@ -652 +652 @@
             response = self.client.get('/raises500/')
             self.assertNotContains(response, "This should not be displayed", status_code=500)
 
+    def test_callable_settings_forbidding_to_set_attributes(self):
+        """
+        Callable settings which forbid to set attributes should not break
+        the debug page (#23070).
+        """
+        class CallableSettingWithSlots(object):
+            __slots__ = []
+
+            def __call__(self):
+                return "This should not be displayed"
+
+        with self.settings(DEBUG=True, WITH_SLOTS=CallableSettingWithSlots()):
+            response = self.client.get('/raises500/')
+            self.assertNotContains(response, "This should not be displayed", status_code=500)
+
     def test_dict_setting_with_non_str_key(self):
         """
         A dict setting containing a non-string key should not break the