this modification is really needed for Zope 2.7.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@18535 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5Type/patches/WorkflowTool.py

@@ -631,8 +631,10 @@ class WorkflowHistoryList(Persistent):
         if index == -1:
             return self._slots[-1]
         elif isinstance(index, (int, long)):
-            # XXX this implementation is not so good, but rarely used.
-            return tuple(self)[index]
+            iterator = self.__iter__()
+            for i in xrange(index):
+                iterator.next()
+            return iterator.next()
         elif isinstance(index, slice):
             return self.__class__((self[x] for x in
                                    xrange(*index.indices(len(self)))))