Fixed #32191 -- Made CookieStorage use RFC 6265 compliant format.

Co-authored-by: Craig Smith <hello@craigiansmith.com.au>

docs/internals/deprecation.txt

@@ -31,6 +31,9 @@ details on these changes.
 
 * ``django.core.cache.backends.memcached.MemcachedCache`` will be removed.
 
+* Support for the pre-Django 3.2 format of messages used by
+  ``django.contrib.messages.storage.cookie.CookieStorage`` will be removed.
+
 .. _deprecation-removed-in-4.0:
 
 4.0

docs/ref/contrib/messages.txt

@@ -69,6 +69,10 @@ Django provides three built-in storage classes in
     to prevent manipulation) to persist notifications across requests. Old
     messages are dropped if the cookie data size would exceed 2048 bytes.
 
+    .. versionchanged:: 3.2
+
+        Messages format was changed to the :rfc:`6265` compliant format.
+
 .. class:: storage.fallback.FallbackStorage
 
     This class first uses ``CookieStorage``, and falls back to using

docs/releases/3.2.txt

@@ -702,6 +702,10 @@ Miscellaneous
 
 * The minimum supported version of SQLite is increased from 3.8.3 to 3.9.0.
 
+* :class:`~django.contrib.messages.storage.cookie.CookieStorage` now stores
+  messages in the :rfc:`6265` compliant format. Support for cookies that use
+  the old format remains until Django 4.1.
+
 .. _deprecated-features-3.2:
 
 Features deprecated in 3.2
@@ -737,3 +741,8 @@ Miscellaneous
   deprecated as ``python-memcached`` has some problems and seems to be
   unmaintained. Use ``django.core.cache.backends.memcached.PyMemcacheCache``
   or ``django.core.cache.backends.memcached.PyLibMCCache`` instead.
+
+* The format of messages used by
+  ``django.contrib.messages.storage.cookie.CookieStorage`` is different from
+  the format generated by older versions of Django. Support for the old format
+  remains until Django 4.1.