Description:
------------
Background: The Pingback option in Geeklog 1.4.1 stops working on PHP 
5.2.2. Pingbacks are implemented using PEAR::XML_RPC and it appears 
that the raw POST data is not getting through.

In other words, and as demonstrated below, raw POST data is not 
available through the $HTTP_RAW_POST_DATA or $GLOBALS
['HTTP_RAW_POST_DATA'] variables, independent of the setting of 
always_populate_raw_post_data in php.ini.

Raw POST data is available through php://input, though.

Switching back to PHP 5.2.1 resolves the problem. The problem also 
does not occur with PHP 4.4.7.

I'll provide two scripts, send.php and receive.php, below to reproduce 
the problem. send.php will send an XML-RPC call to receive.php which 
would normally display the XML data. They should be located on the 
same server (running PHP 5.2.2), in the server's webroot, i.e. 
www.example.com/send.php and www.example.com/receive.php. To 
reproduce, simply call up send.php.

This issue has also been reported on php.internals:

http://news.php.net/php.internals/29103 and
http://news.php.net/php.internals/29202 ff.

Reproduce code:
---------------
send.php:

<?php

require_once 'XML/RPC.php';

$sourceURI = 'http://www.example.com/'; // doesn't matter here
$targetURI = $sourceURI;

$client = new XML_RPC_Client('/receive.php', $_SERVER['HTTP_HOST']);
$client->setDebug(1);
$msg = new XML_RPC_Message('pingback.ping',
        array(new XML_RPC_Value($sourceURI, 'string'),
              new XML_RPC_Value($targetURI, 'string')));

$response = $client->send($msg, 0, 'http');

?>

receive.php:

<?php

print_r(getallheaders());

echo $GLOBALS['HTTP_RAW_POST_DATA'] . "\n\n";

?>

Expected result:
----------------
---GOT---
HTTP/1.1 200 OK
Date: Sat, 05 May 2007 08:01:49 GMT
Server: Apache/1.3.37 (Unix) PHP/5.2.2
X-Powered-By: PHP/5.2.2
Connection: close
Content-Type: text/html

<?xml version="1.0" encoding="UTF-8"?>
<methodCall>
<methodName>pingback.ping</methodName>
<params>
<param>
<value><string>http://www.example.com/</string></value>
</param>
<param>
<value><string>http://www.example.com/</string></value>
</param>
</params>
</methodCall>

---END---

Actual result:
--------------
---GOT---
HTTP/1.1 200 OK
Date: Fri, 04 May 2007 20:07:58 GMT
Server: Apache/1.3.37 (Unix) PHP/5.2.2
X-Powered-By: PHP/5.2.2
Connection: close
Content-Type: text/html

Array
(
    [Content-Length] => 282
    [Content-Type] => text/xml
    [Host] => myhost.example.com
    [User-Agent] => PEAR XML_RPC
)
<br />
<b>Notice</b>:  Undefined index:  HTTP_RAW_POST_DATA in <b>/usr/local/
apache/vhost/geeklog/public_html/receive.php</b> on line <b>5</b><br /
>

---END---