Description:
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Attempting to use readfile() to send large (over 250MB) binary objects causes PHP 5.0.1 to hang or the web server to send a 302 error.  Reverting back to PHP 4.3.8 resolves the issue.

Using fopen() and fpassthru() only makes the issue worse.

We are using IIS 6 and the PHP ISAPI script engine.

Reproduce code:
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header("Content-Type: application/force-download");
header("Content-Type: application/octet-stream");
header("Content-Type: application/download");
header("Content-Disposition: attachment; filename=".basename($filename).";");
header("Content-Transfer-Encoding: binary");
header("Content-Length: ".filesize($filename));

readfile("$filename"); 
exit(); 


Expected result:
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PHP 5 has an issue with sending large binary files.  This should be resolved.