Description:
------------
When the method called in xmlrpc_server_call_method() returns an array where the keys are numeric but non-sequential it does not include the keys in the xml response, so when that response is decoded by the client all the keys are resequenced from zero. This means that all the original keys are lost.

Reproduce code:
---------------
function indexedArray ( $func, $params) {
    return array(1=>'One', 3=>'Three', 5=>'Five');
} // indexedArray
$server = xmlrpc_server_create();
$result = xmlrpc_server_register_method($server, 'indexedArray', 'indexedArray');
$HTTP_RAW_POST_DATA = <<<EOD
<?xml version="1.0" encoding="UTF-8"?>
<methodCall>
<methodName>indexedArray</methodName>
<params />
</methodCall>
EOD;
$response = xmlrpc_server_call_method($server, $HTTP_RAW_POST_DATA, null);
$array = xmlrpc_decode($response);

Expected result:
----------------
The contents of $array should read (1=>'One', 3=>'Three', 5=>'Five'). This is because the xml document does not contain any <name> elements for each <member>.

Actual result:
--------------
The contents of $array is (0=>'One', 1=>'Three', 2=>'Five')