Fix X-Y-Z node replacement.  X is a bad node that we need to bring up a new node to replace.
Y is a new node that is supposed to replace X but dies in the middle.  Z comes up to replace X but
think it should replace Y.  This fix helps Z to identify X, the original bad node.
Merge pull request #332 from timiblossom/master

Fix X-Y-Z node replacement.  X is a bad node that we need to bring up a ...