--- old/jaxp/src/javax/xml/xpath/XPathException.java	2013-05-27 01:29:06.025500812 +0400
+++ new/jaxp/src/javax/xml/xpath/XPathException.java	2013-05-27 01:29:05.961500813 +0400
@@ -26,6 +26,10 @@
 package javax.xml.xpath;
 
 import java.io.PrintWriter;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.ObjectStreamField;
 
 /**
  * <code>XPathException</code> represents a generic XPath exception.</p>
@@ -35,9 +39,11 @@
  * @since 1.5
  */
 public class XPathException extends Exception {
-
-    private final Throwable cause;
-
+    
+    private static final ObjectStreamField[] serialPersistentFields = {
+        new ObjectStreamField( "cause", Throwable.class )
+    };
+    
     /**
      * <p>Stream Unique Identifier.</p>
      */
@@ -62,9 +68,8 @@
         if ( message == null ) {
             throw new NullPointerException ( "message can't be null");
         }
-        this.cause = null;
     }
-
+    
     /**
      * <p>Constructs a new <code>XPathException</code>
      * with the specified <code>cause</code>.</p>
@@ -77,8 +82,7 @@
      * @throws NullPointerException if <code>cause</code> is <code>null</code>.
      */
     public XPathException(Throwable cause) {
-        super();
-        this.cause = cause;
+        super(cause);
         if ( cause == null ) {
             throw new NullPointerException ( "cause can't be null");
         }
@@ -90,8 +94,42 @@
      * @return Cause of this XPathException.
      */
     public Throwable getCause() {
-        return cause;
+        return super.getCause();
+    }
+    
+    /**
+     * Writes "cause" field to the stream. 
+     * The cause is got from the parent class.
+     * 
+     * @param out stream used for serialization.
+     * @throws IOException thrown by <code>ObjectOutputStream</code>
+     * 
+     */
+    private void writeObject(ObjectOutputStream out) 
+            throws IOException 
+    {
+        ObjectOutputStream.PutField fields = out.putFields();
+        fields.put("cause", (Throwable) super.getCause());
+        out.writeFields();
     }
+    
+    /**
+     * Reads the "cause" field from the stream.
+     * And initializes the "cause" if it wasn't 
+     * done before.
+     * 
+     * @param in stream used for deserialization
+     * @throws IOException thrown by <code>ObjectInputStream</code>
+     * @throws ClassNotFoundException  thrown by <code>ObjectInputStream</code>
+     */
+    private void readObject(ObjectInputStream in) 
+            throws IOException, ClassNotFoundException 
+    {
+        ObjectInputStream.GetField fields = in.readFields();
+        Throwable scause = (Throwable) fields.get("cause", null);
+        if (super.getCause() == null && scause != null)
+            super.initCause(scause);
+    }    
 
     /**
      * <p>Print stack trace to specified <code>PrintStream</code>.</p>
--- /dev/null	2013-05-27 00:30:36.211070918 +0400
+++ new/jdk/test/com/sun/org/apache/xpath/XPathExceptionInitCause.java	2013-05-27 01:29:06.273500811 +0400
@@ -0,0 +1,78 @@
+/*
+ * @test
+ * @bug 8009579
+ * @summary The initCause() incorrectly initialise the cause in
+ * XPathException class when used with XPathException(String)
+ * constructor.
+ * @run main XPathExceptionInitCause
+ * @author aleksej.efimov@oracle.com
+ */
+
+import javax.xml.xpath.XPathException;
+import java.io.ByteArrayOutputStream;
+import java.io.ByteArrayInputStream;
+import java.io.ObjectOutputStream;
+import java.io.ObjectInputStream;
+import java.io.IOException;
+
+public class XPathExceptionInitCause {
+
+    //Serialize XPathException
+    static byte [] pickleXPE(XPathException xpe) throws IOException {
+        ByteArrayOutputStream bos =  new ByteArrayOutputStream();
+        ObjectOutputStream xpeos = new ObjectOutputStream(bos);
+        xpeos.writeObject(xpe);
+        xpeos.close();
+        return bos.toByteArray();
+    }
+
+    //Deserialize XPathException
+    static XPathException unpickleXPE(byte [] ser) 
+            throws IOException, ClassNotFoundException {
+        XPathException xpe;
+        ByteArrayInputStream bis = new ByteArrayInputStream(ser);
+        ObjectInputStream xpeis = new ObjectInputStream(bis);
+        xpe = (XPathException) xpeis.readObject();
+        xpeis.close();
+        return xpe;
+    }
+
+    public static void main(String[] args) throws Exception {
+        Throwable cause = new Throwable("message 1");
+        XPathException xpathexcep = new XPathException("message 2");
+
+        //Test XPE initCause() method 
+        xpathexcep.initCause(cause);
+        System.out.println("getCause() result: '" + xpathexcep.getCause()
+                + "' Cause itself: '" + cause + "'");
+        if (!xpathexcep.getCause().toString().equals(cause.toString())) {
+            throw new Exception("Incorrect cause is set by initCause()");
+        }
+
+        //Test serialization/deserialization of initialized XPE
+        byte [] xpeserial;
+        XPathException xpedeser;
+        xpeserial = pickleXPE(xpathexcep);
+        xpedeser = unpickleXPE(xpeserial);
+        System.out.println("Serialized XPE: message='" + xpathexcep.getMessage()
+                + "' cause='" + xpathexcep.getCause().toString() + "'");
+        System.out.println("Deserialized XPE: message='" + xpedeser.getMessage()
+                + "' cause='" + xpedeser.getCause().toString()+"'");
+        if(xpedeser.getCause() == null || 
+                !xpedeser.getCause().toString().equals(cause.toString()) ||
+                !xpedeser.getMessage().toString().equals("message 2") )
+            throw new Exception("XPathException incorrectly serialized/deserialized");
+
+        //Test serialization/deserialization of uninitialized cause in XPE
+        XPathException xpeuninit = new XPathException("uninitialized cause");
+        xpeserial = pickleXPE(xpeuninit);
+        xpedeser = unpickleXPE(xpeserial);
+        System.out.println("Serialized XPE: message='" + xpeuninit.getMessage()
+                + "' cause='" + xpeuninit.getCause()+"'");
+        System.out.println("Deserialized XPE: message='" + xpedeser.getMessage()
+                + "' cause='" + xpedeser.getCause()+"'");
+        if(xpedeser.getCause() != null ||
+                !xpedeser.getMessage().toString().equals("uninitialized cause") )
+            throw new Exception("XPathException incorrectly serialized/deserialized");
+    }
+}