Issue #4176: Pickle would crash the interpreter when a __reduce__ function
does not return an iterator for the 4th and 5th items.
(sequence-like and mapping-like state)

Backport of r67049.
diff --git a/Misc/NEWS b/Misc/NEWS
index e62bb7c..6e8a25a 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,9 @@
 Core and builtins
 -----------------
 
+- Issue #4176: Fixed a crash when pickling an object which ``__reduce__``
+  method does not return iterators for the 4th and 5th items.
+
 - Issue #3967: Fixed a crash in the count() and find() methods of string-like
   objects, when the "start" parameter is a huge value.