how to debug RB_TREE for memory corruption?

[Davide Italiano]

Was the node you're removing actually part of the tree?
I had a similar issue some time ago because I've tried insert two
nodes w/ the same key and then remove then.
In practice, the second INSERT operation failed (due to the definition
of key in a BST), and so I was trying to remove a node that wasn't
actually inserted.
Can you provide a snippet of code o some minimal testcase in order to
reproduce the error?

Regards

Davide