diff -r d564695b67bb Doc/library/http.cookies.rst
--- a/Doc/library/http.cookies.rst	Fri Mar 20 00:27:28 2015 +0100
+++ b/Doc/library/http.cookies.rst	Thu Mar 19 22:10:31 2015 -0700
@@ -144,6 +144,23 @@
    The keys are case-insensitive.
 
 
+.. versionchanged:: 3.5
+
+   :func:`Morsel.__eq__` now takes :attr:`Morsel.key` and :attr:`Morsel.value`
+   into account.
+
+.. versionchanged:: 3.5
+
+   :func:`Morsel.copy` now results in a :class:`Morsel` instance rather than a
+   *dict*
+
+.. versionchanged:: 3.5
+
+   The behaviour of :func:`Morsel.update` is now consistent with
+   :func:`Morsel.__setitem__` in that setting invalid attributes will raise an
+   exception.
+
+
 .. attribute:: Morsel.value
 
    The value of the cookie.
@@ -175,6 +192,11 @@
 
    Set the *key*, *value* and *coded_value* attributes.
 
+   .. deprecated:: 3.5
+
+      The undocumented *LegalChars* parameter is ignored and will be removed in
+      future versions.
+
 
 .. method:: Morsel.isReservedKey(K)
 
diff -r d564695b67bb Doc/whatsnew/3.5.rst
--- a/Doc/whatsnew/3.5.rst	Fri Mar 20 00:27:28 2015 +0100
+++ b/Doc/whatsnew/3.5.rst	Thu Mar 19 22:10:31 2015 -0700
@@ -518,6 +518,9 @@
   :func:`~http.cookies.Morsel.set` method in order to avoid the deprecation
   warning.
 
+* The undocumented *LegalChars* parameter of :func:`~http.cookies.Morsel.set`
+  has been deprecated and is now ignored.
+
 
 Deprecated functions and types of the C API
 -------------------------------------------
diff -r d564695b67bb Lib/http/cookies.py
--- a/Lib/http/cookies.py	Fri Mar 20 00:27:28 2015 +0100
+++ b/Lib/http/cookies.py	Thu Mar 19 22:10:31 2015 -0700
@@ -366,7 +366,13 @@
     def isReservedKey(self, K):
         return K.lower() in self._reserved
 
-    def set(self, key, val, coded_val):
+    def set(self, key, val, coded_val, LegalChars=_LegalChars):
+        if LegalChars != _LegalChars:
+            import warnings
+            warnings.warn(
+                'LegalChars parameter is deprecated, ignored and will '
+                'be removed in future versions.', DeprecationWarning)
+
         if key.lower() in self._reserved:
             raise CookieError('Attempt to set a reserved key %r' % (key,))
         if not _is_legal_key(key):
diff -r d564695b67bb Lib/test/test_http_cookies.py
--- a/Lib/test/test_http_cookies.py	Fri Mar 20 00:27:28 2015 +0100
+++ b/Lib/test/test_http_cookies.py	Thu Mar 19 22:10:31 2015 -0700
@@ -261,6 +261,8 @@
             morsel.value = ''
         with self.assertWarnsRegex(DeprecationWarning, r'\bcoded_value\b'):
             morsel.coded_value = ''
+        with self.assertWarnsRegex(DeprecationWarning, r'\bLegalChars\b'):
+            morsel.set('key', 'value', 'coded_value', LegalChars='.*')
 
     def test_eq(self):
         base_case = ('key', 'value', '"value"')