Description:
------------
PHP 5.5.9-1ubuntu4.17 (cli) (built: May 19 2016 19:05:57) 
Copyright (c) 1997-2014 The PHP Group
Zend Engine v2.5.0, Copyright (c) 1998-2014 Zend Technologies
    with Zend OPcache v7.0.3, Copyright (c) 1999-2014, by Zend Technologies
====================================================================
This was also present in PHP 5.3.X versions

When calling the substr function and passing it a length of 08 or 09 - it seems to return a null.  Passing lengths of 8 or 9 return expected results. 


Test script:
---------------
<?PHP
$buffer = "This should work as expected.";
echo substr($buffer , 0 , 1)  ."\n";
echo substr($buffer , 0 , 01) ."\n";
echo substr($buffer , 0 , 7)  ."\n";
echo substr($buffer , 0 , 07) ."\n";
echo substr($buffer , 0 , 8)  ."\n";
echo substr($buffer , 0 , 08) ."\n"; //FAILS
echo substr($buffer , 0 , 9)  ."\n";
echo substr($buffer , 0 , 09) ."\n"; //FAILS
echo substr($buffer , 0 , 10) ."\n";
echo substr($buffer , 0 , 10) ."\n";
?>