Description:
------------
I've checked out DOM method is_blank_node(), which checks whether a node is empty or not. The methode is_blank_node seems to me not working correctly and returns nothing.  

Reproduce code:
---------------
XML-Code with empty nodes:

<?xml version="1.0"?>
<userliste>
  <user>
    <name/>
    <passwort/>
    <datum/>
    <zeit/>
  </user>
</userliste>

PHP-Code to read and to use is_blank_node:

<?php
 if(!$dom = domxml_open_file("e:/htdocs/user.xml")) {
  echo "Error while parsing the document\n";
  exit;
}
 $root=$dom->document_element();
 print($root->is_blank_node());
 $node=$dom->get_elements_by_tagname("name");
 print ($node[0]->node_name());
 print ($node[0]->is_blank_node());
 if ($node[0]->is_blank_node()) {
  print("empty");
 }
?>


Expected result:
----------------
The PHP-code checks whether <name> is empty or not. I'v expected that is_blank_node returns true.  

Actual result:
--------------
is_blank_node returns nothing.