Description:
------------
Something in PHP5 running under apache2 under Ubuntu 9.10 is not fully 64 bit 
aware on a 64 bit system. PHP scripts run under Apache correctly under Ubuntu 
8.04 (PHP 5.2.4). Under Ubuntu 9.10 (PHP 5.2.10) and 10.04 (PHP 5.3.2), some 
place a value is being treated as 32 bits on a 64 bit system and is wrapping 
instead of using full 64 bits. Related to sending large data (> 4G) in response 
to an HTTP post request.

Did not test with Ubuntu 8.10 or 9.04 - both PHP 5.2.6.

What happens: Data aborts based on wrap. Calculated number of bytes to be served 
are correct (>4G) as listed in the HTTP length header. Actual bytes served are 
(size) && 0xFFFFFFFF instead of (size) && 0xFFFFFFFFFFFFFFFF on 64 bit system.

Most of data is being transfered via fpassthru($openFileHandle) call, providing 
>4G bytes of data.

Test script:
---------------
<?php 
    header("Connection: close");
// NOTE:  File test.txt needs to be more than 2^32 bytes.  Pick a large file, over 0x100000000 bytes 
//        in size, such as http://cdimage.debian.org/debian-cd/5.0.4/amd64/iso-dvd/debian-504-amd64-DVD-1.iso 
    $name = "/var/www/test.txt";
    $fs = filesize($name);
    $fp = fopen($name,'rb');
    $httpByteLen = $fs;
    header("Connection: close");
    header("Content-Type: application/octet-stream");
    header("Content-Length: " . $httpByteLen);
    header("HTTP/1.1 200 OK");
    set_time_limit(0);
    fpassthru($fp);
    exit;
?>

Expected result:
----------------
The entire ISO file to be downloaded.

Actual result:
--------------
Tested using the test script (attached), and using the suggested debian dvd .iso 
image as the input file.  The ISO is 4,697,126,912 bytes. Download socket is 
closed after 402,159,616 bytes, which again is the file size & 0xFFFFFFFF.