Description:
------------
Wrong behaviour when i use is_dir() on localhost. Works as expected on external php.

Test script:
---------------
[19] boris> $ftp = ftp_connect('localhost');
 → resource(39) of type (FTP Buffer)

[20] boris> ftp_login($ftp, 'message', 'password');
 → true

[22] boris> ftp_nlist($ftp,'.');
 → array(
  42 => 'Applications',
  43 => 'Desktop',
  44 => 'Documents',
  45 => 'Downloads',
  46 => 'Dropbox',
  47 => 'fixtures',
  49 => 'Library',
  52 => 'Movies',
  53 => 'Music',
  56 => 'Pictures',
  57 => 'Public',
  58 => 'springsource',
  59 => 'temporary_fixtures',
  61 => 'www'
)

[23] boris> is_dir('ftp://message:password@127.0.0.1/www');
 → false

[24] boris> is_dir('ftp://message:password@127.0.0.1/temporary_fixtures');
 → false

[25] boris> is_dir('ftp://message:password@127.0.0.1/');
 → true

[26] boris> is_dir('/Users/message/www');
 → true


Expected result:
----------------
[23] boris> is_dir('ftp://message:password@127.0.0.1/www');
 → true

Actual result:
--------------
[23] boris> is_dir('ftp://message:password@127.0.0.1/www');
 → false