Fixing JIRA Issue #1651: https://issues.apache.org/jira/browse/XERCESJ-1651. \w should be processed as [#x0000-#x10FFFF]-[\p{P}\p{Z}\p{C}] as per the XML Schema specification.
xerces/java/trunk/src/org/apache/xerces/impl/xpath/regex/ParserForXMLSchema.java