Description:
------------
if you take a look at the test script, the output_compression shouldn't have been sent, as there is an output before it,

however, on Ubuntu 15.10, Using php5-fpm nginx, the headers get sent anyway regardless if there is content before it or not, and that's breaks browsers, and shows errors such as 

Chrome:
This webpage is not available - ERR_CONTENT_DECODING_FAILED

Firefox:
Content Encoding Error

The page you are trying to view cannot be shown because it uses an invalid or unsupported form of compression.


Test script:
---------------
<?php

$obj = (object) [
    'foo' => 'bar'
];

var_dump( $obj );

if ( !headers_sent() )
{
    ini_set( 'zlib.output_compression', 1 );
}


Expected result:
----------------
the header shouldn't have been sent.

Actual result:
--------------
the header get sent which garbled the output, which in turn breaks the output_compression, and causes the browsers to show error.