Fixed #18781 -- Reduced max session cookie size.

django/contrib/messages/storage/cookie.py

@@ -46,10 +46,10 @@ class CookieStorage(BaseStorage):
     Stores messages in a cookie.
     """
     cookie_name = 'messages'
-    # We should be able to store 4K in a cookie, but Internet Explorer
-    # imposes 4K as the *total* limit for a domain.  To allow other
-    # cookies, we go for 3/4 of 4K.
-    max_cookie_size = 3072
+    # uwsgi's default configuration enforces a maximum size of 4kb for all the
+    # HTTP headers. In order to leave some room for other cookies and headers,
+    # restrict the session cookie to 1/2 of 4kb. See #18781.
+    max_cookie_size = 2048
     not_finished = '__messagesnotfinished__'
 
     def _get(self, *args, **kwargs):

django/contrib/messages/tests/base.py

@@ -152,7 +152,7 @@ class BaseTest(TestCase):
         cycle.
         """
         data = {
-            'messages': ['Test message %d' % x for x in range(10)],
+            'messages': ['Test message %d' % x for x in range(5)],
         }
         show_url = reverse('django.contrib.messages.tests.urls.show')
         for level in ('debug', 'info', 'success', 'warning', 'error'):
@@ -170,7 +170,7 @@ class BaseTest(TestCase):
     @override_settings(MESSAGE_LEVEL=constants.DEBUG)
     def test_with_template_response(self):
         data = {
-            'messages': ['Test message %d' % x for x in range(10)],
+            'messages': ['Test message %d' % x for x in range(5)],
         }
         show_url = reverse('django.contrib.messages.tests.urls.show_template_response')
         for level in self.levels.keys():
@@ -194,7 +194,7 @@ class BaseTest(TestCase):
         before a GET.
         """
         data = {
-            'messages': ['Test message %d' % x for x in range(10)],
+            'messages': ['Test message %d' % x for x in range(5)],
         }
         show_url = reverse('django.contrib.messages.tests.urls.show')
         messages = []
@@ -226,7 +226,7 @@ class BaseTest(TestCase):
         when one attempts to store a message.
         """
         data = {
-            'messages': ['Test message %d' % x for x in range(10)],
+            'messages': ['Test message %d' % x for x in range(5)],
         }
         show_url = reverse('django.contrib.messages.tests.urls.show')
         for level in ('debug', 'info', 'success', 'warning', 'error'):
@@ -251,7 +251,7 @@ class BaseTest(TestCase):
         raised if 'fail_silently' = True
         """
         data = {
-            'messages': ['Test message %d' % x for x in range(10)],
+            'messages': ['Test message %d' % x for x in range(5)],
             'fail_silently': True,
         }
         show_url = reverse('django.contrib.messages.tests.urls.show')