[xmlsec] debugging transforms

[Alex Salcianu]

Hello!

I'm currently using XPath Filter 2.0 transforms to specify
the parts of the document that should go into a reference.
My references look like

<Reference>
  <Transforms>
    <Transform Algorithm="http://www.w3.org/2002/06/xmldsig-filter2">
      <XPath xmlns="http://www.w3.org/2002/06/xmldsig-filter2" 
Filter="intersect">...</XPath>
      <XPath xmlns="http://www.w3.org/2002/06/xmldsig-filter2" 
Filter="subtract">...</XPath>
    </Transform>
  </Transforms>
  <DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>
  <DigestValue/>
</Reference>

[ for brevity, I omitted the actual XPath expressions ]

For debugging, I would like very much to be able to print all nodes that
are selected by this succession of XPath2's (this way, I can check that
XMLSec selects the nodes that I actually intend to select).

What would be the best function inside xmlsec to instrument for this 
purpose?

XMLSec already contains a function (xmlSecNodeSetDebugDump) that prints 
a set
of nodes.

Thanks,

Alex