Fix a bug in the XPathException(Throwable) constructor.

Pass the message from the cause Throwable to the super constructor,
so that the getMessage() method on this XPathException would
return the message of the cause.


git-svn-id: https://svn.apache.org/repos/asf/xml/commons/trunk@226234 13f79535-47bb-0310-9956-ffa450edef68

java/external/src/javax/xml/xpath/XPathException.java

@@ -63,7 +63,7 @@ public class XPathException extends Exception {
      * @throws NullPointerException if <code>cause</code> is <code>null</code>.
      */
     public XPathException(Throwable cause) {
-        super();
+        super(cause == null ? null : cause.toString());
         this.cause = cause;
         if ( cause == null ) {
             throw new NullPointerException ( "cause can't be null");