Forward port only Py3k relevant change in r65642 (giving it a Py3k NEWS entry anyway because of the difference in the changes between the two branches)
diff --git a/Misc/NEWS b/Misc/NEWS
index afbe989..78cae29 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -30,6 +30,12 @@
 Library
 -------
 
+- Issue #2235: numbers.Number now blocks inheritance of the default id()
+  based hash because that hash mechanism is not correct for numeric types.
+  All concrete numeric types that inherit from Number (rather than just
+  registering with it) must explicitly provide a hash implementation in
+  order for their instances to be hashable.
+
 - Issue #2676: in the email package, content-type parsing was hanging on
   pathological input because of quadratic or exponential behaviour of a
   regular expression.