Description:
------------
Documentation at http://php.net/readdir explains that

> This function may return Boolean FALSE, but may also return a non-Boolean value which evaluates to FALSE, such as 0 or "". Please read the section on Booleans for more information. Use the === operator for testing the return value of this function.

That was true for PHP 5.2.x and not so for 5.3.x:

# php -r 'var_dump(phpversion(), @readdir(false), @readdir(false)===false);'
string(8) "5.2.11-2"
bool(false)
bool(true)

# php -r 'var_dump(phpversion(), @readdir(false), @readdir(false)===false);'
string(7) "5.3.2-1"
NULL
bool(false)

This can make loop while (false !== ($file = readdir($handle))) {...} infinite if $handle was not checked beforehand.

Please consider to be more backward-compatible if this not cost much.

Thanks!


Test script:
---------------
php -r 'var_dump(@readdir(false), @readdir(false)===false);'             


Expected result:
----------------
bool(false)
bool(true)


Actual result:
--------------
NULL
bool(false)