Description:
------------
Putting an array through xmlrpc_encode() after referencing one or more array elements, results in missing data in the XML output. The referenced elements are excluded.
In this case, the 2nd element of the array ("a") is missing.

Test script:
---------------
<?php

$ar = array(4, "a", 7);
$v = &$ar[1];
unset($v);

echo xmlrpc_encode($ar);

Expected result:
----------------
<?xml version="1.0" encoding="utf-8"?>
<params>
<param>
 <value>
  <array>
   <data>
    <value>
     <int>4</int>
    </value>
    <value>
     <string>a</string>
    </value>
    <value>
     <int>7</int>
    </value>
   </data>
  </array>
 </value>
</param>
</params>

Actual result:
--------------
<?xml version="1.0" encoding="utf-8"?>
<params>
<param>
 <value>
  <array>
   <data>
    <value>
     <int>4</int>
    </value>
    <value>
     <int>7</int>
    </value>
   </data>
  </array>
 </value>
</param>
</params>