SF patch #1005778, Fix seg fault if list object is modified during list.index()

Backport candidate
diff --git a/Misc/NEWS b/Misc/NEWS
index c4a1cf1..c1c7867 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,10 @@
 Core and builtins
 -----------------
 
+- SF patch #1005778.  Fix a seg fault if the list size changed while
+  calling list.index().  This could happen if a rich comparison function
+  modified the list.
+
 - The ``func_name`` (a.k.a. ``__name__``) attribute of user-defined
   functions is now writable.