SimpleSAML_Metadata_SAMLParser: Fix bug in signature validation.

The signature validation removes the signature element from the DOM
tree, which causes the metadata parsing to skip the DOM node following
the signature element. Normally this element would be a text node, but
it could also be a SSODescriptor-element.

git-svn-id: https://simplesamlphp.googlecode.com/svn/trunk@1931 44740490-163a-0410-bde0-09ae8108e29a

lib/SimpleSAML/Metadata/SAMLParser.php

@@ -1406,6 +1406,14 @@ class SimpleSAML_Metadata_SAMLParser {
 		$entityDescriptor = $element->parentNode;
 		assert('$entityDescriptor instanceof DOMElement');
 
+		/*
+		 * Make a copy of the entity descriptor, so that the validator can
+		 * change the DOM tree in any way it wants.
+		 */
+		$doc = new DOMDocument();
+		$entityDescriptor = $doc->importNode($entityDescriptor, TRUE);
+		$doc->appendChild($entityDescriptor);
+
 		/* Attempt to check the signature. */
 		try {
 			$validator = new SimpleSAML_XML_Validator($entityDescriptor, 'ID');