Description:
------------
When making a PHP request, if the Content-type request header 
is undefined, $HTTP_RAW_POST_DATA is empty (or undefined, 
depending on the related ini setting).

Reading from the input stream works correctly, and will read 
all content if the content-type is set or not.

Reproduce code:
---------------
<?php

/* PRINT DEBUG INFO */

// Request method
echo "Request Method: ".$_SERVER['REQUEST_METHOD']."\n";

// HTTP_RAW_POST_DATA
echo "HTTP_RAW_POST_DATA: ".$HTTP_RAW_POST_DATA."\n";

// Input socket
$inputSocket = fopen('php://input','rb');
$contents = stream_get_contents($inputSocket);
fclose($inputSocket);

echo "Input socket: ".$contents."\n";

?>

Expected result:
----------------
When Content-type request header not sent:

Request Method: POST
HTTP_RAW_POST_DATA: 
Input socket: post_contents

Actual result:
--------------
It should be the same as if reading from the input stream:

Request Method: POST
HTTP_RAW_POST_DATA: post_contents
Input socket: post_contents