A PerfixResolver Question

["Gaur, Manish" <Mg...@rsasecurity.COM>]

Hi,

If I were to evaluate the expression "not(ancestor-or-self::A:Signature)"
on the following input Document, the result should be all nodes 
except the Signature node.

<DocumentRoot>
  <ManyNodes1>
  </ManyNodes1>
  <A:Signature xmlns:A="someuri"/>
  <ManyNodes1>
  </ManyNodes1>
  <ManyNodes1>
  </ManyNodes1>
</DocumentRoot>

This is what I am doing,

//..(decls and inits)
const char *expression = "not(ancestor-or-self::A:Signature)" ;

// select all nodes
const XObjectPtr theResult(
  theEvaluator.evaluate(
  theDOMSupport,
  theDocument,
 
XalanDOMString("(/descendant-or-self::node()/.|//@*|//namespace::*)").c_str(
))) ;

// for each node evaluate expression
for (NodeRefList::size_type j = 0; j < (theResult->nodeset()).getLength();
++j)
{
  XalanNode *thisNode = (theResult->nodeset()).item(j) ;
  
  XPathEvaluator  objEvaluator ;
  // evaluate expression on node
  const XObjectPtr objPointer(
    objEvaluator.evaluate(
      theDOMSupport,
      thisNode,
      XalanDOMString(expression).c_str(),
      ElementPrefixResolverProxy(
        theDocument->getDocumentElement(),
        XPathEnvSupportDefault(), 
        theDOMSupport))) ;

  if(objPointer->boolean())
    // do something
}

As you notice, I am using ElementPrefixResolverProxy and initializing 
the namespaceContext as the documentElement. 
Ofcourse, this fails with an XSLException on the first node in the nodelist
itself (which is the document root node), as it doesn't know about the 
xmlns:A namespace yet so it cannot resolve it. 

My question is, what is the right namespaceContext for 
expressions (and documents) like these?? 
or am I missing something fundamental here?


Your help is greatly appreciated.

Regards,
/Manish

PS: Sorry for such a long message. Please feel free to ask for
clarifications.