Description:
------------
According to the documentation ftp_nlist should only return array or false value
but if parameters are incorrect it may return a null value (see test script).
I don't know if it may be useful in some situations. 
Hence I don't know if the code should be corrected or if the documentation should be completed.
Let me know if you think the problem is in the documentation. In that case, I'll modify it.

Best regards,
   Laurent Lyaudet

Test script:
---------------
<?php
var_dump(ftp_nlist(false, ''));
?>


Expected result:
----------------
false


Actual result:
--------------
null