diff -r b758351d191f -r cc9b7e14412b web/lib/django/contrib/messages/middleware.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/web/lib/django/contrib/messages/middleware.py	Tue May 25 02:43:45 2010 +0200
@@ -0,0 +1,26 @@
+from django.conf import settings
+from django.contrib.messages.storage import default_storage
+
+
+class MessageMiddleware(object):
+    """
+    Middleware that handles temporary messages.
+    """
+
+    def process_request(self, request):
+        request._messages = default_storage(request)
+
+    def process_response(self, request, response):
+        """
+        Updates the storage backend (i.e., saves the messages).
+
+        If not all messages could not be stored and ``DEBUG`` is ``True``, a
+        ``ValueError`` is raised.
+        """
+        # A higher middleware layer may return a request which does not contain
+        # messages storage, so make no assumption that it will be there.
+        if hasattr(request, '_messages'):
+            unstored_messages = request._messages.update(response)
+            if unstored_messages and settings.DEBUG:
+                raise ValueError('Not all temporary messages could be stored.')
+        return response