Description:
------------
Apache2 module.

PHP-recommended.ini / default
output_handler =
zlib.output_compression = Off

ob_start('ob_gzhandler') doesn't work as expected. The same if wrapped into a function.


Reproduce code:
---------------
#1
ob_start('ob_gzhandler');
echo "Something";
ob_end_flush();
echo "Hello World";

// Call undefined function
call_some_user_function();

#2
function compress_data($output)
{
  return ob_gzhandler($output);
}

ob_start('compress_data');
echo "Something<br/>";
ob_end_flush();
echo "Hello World";

// Call undefined function.
call_some_user_function();


Expected result:
----------------
#1
Something
Hello World
Fatal error: Call to undefined function call_some_user_function() in some_file.php........

#2
Something
Hello World
Fatal error: Call to undefined function call_some_user_function() in some_file.php........

Actual result:
--------------
#1
Something

Nothing happens, no fatal error at all, in fact, looks like there's no more processing from that point on.

#2
Hello World
Fatal error: Call to undefined function call_some_user_function() in some_file.php........

Where's the buffer?