Description:
------------
When using substr() on v.7 RC2 on my local machine, I am getting different results than when I run the same script on my Linux webserver running v. 5.6.11

Test script:
---------------
<?php
error_reporting(E_ALL);
ob_start();
?>
resources/layout.css
resources/jquery.fancybox.css
<?php
$files = ob_get_clean();
$fs = explode("\n", $files);

foreach($fs as $f) {
	$ext = substr($f, strrpos($f, "."), strlen($f));
	$ext_trimmed = trim($ext);
	var_dump($ext, $ext_trimmed);
}
?>

Expected result:
----------------
string(4) ".css"
string(4) ".css"
string(4) ".css"
string(4) ".css"
bool(false)
string(0) ""


Actual result:
--------------
string(5) ".css"
string(4) ".css"
string(5) ".css"
string(4) ".css"
string(0) ""
string(0) ""