bug#8346: 24.0.50; ftp broken

[Devon Sean McCullough]

Starting from emacs -Q -q

emacs-version "24.0.50.2"
(dired "/ftp@ftp.gnu.org:")
Debugger entered--Lisp error: (error "Unable to obtain CWD")
  signal(error ("Unable to obtain CWD"))
  byte-code("\203\305        G!\203\n\306>\203\307\207\203&\305        
G!\203&\n\310>\203&\207\311\f@\fA\"\207" [completion localname operation 
filename err zerop (file-exists-p file-directory-p) t (expand-file-name 
file-name-as-directory) signal] 3)
  tramp-file-name-handler(expand-file-name "/ftp@ftp.gnu.org:" nil)
  expand-file-name("/ftp@ftp.gnu.org:" nil)
  apply(expand-file-name ("/ftp@ftp.gnu.org:" nil))
  tramp-completion-run-real-handler(expand-file-name ("/ftp@ftp.gnu.org:" nil))
  tramp-completion-file-name-handler(expand-file-name "/ftp@ftp.gnu.org:" nil)
  expand-file-name("/ftp@ftp.gnu.org:")
  dired-noselect("/ftp@ftp.gnu.org:" nil)
  dired("/ftp@ftp.gnu.org:")
  eval((dired "/ftp@ftp.gnu.org:"))
  eval-last-sexp-1(nil)
  eval-last-sexp(nil)
  call-interactively(eval-last-sexp nil nil)

In GNU Emacs 24.0.50.2 (x86_64-apple-darwin10.6.0, NS apple-appkit-1038.35)
 of 2011-03-13 on new-host-3.home
Windowing system distributor `Apple', version 10.3.1038
configured using `configure  '--with-ns''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: en_US.utf-8
  value of $LC_CTYPE: en_US.utf-8
  value of $LC_MESSAGES: en_US.utf-8
  value of $LC_MONETARY: en_US.utf-8
  value of $LC_NUMERIC: en_US.utf-8
  value of $LC_TIME: en_US.utf-8
  value of $LANG: en_US.utf-8
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default enable-multibyte-characters: t

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
C-y <up> SPC C-u C-x C-e <down> <down> C-x C-e C-x 
h M-w q <return> C-y M-x r e p o r t SPC e m SPC SPC 
<return>

Recent messages:
byte-code: End of buffer
Opening FTP connection to ftp.gnu.org...done
Logging in as user ftp@ftp.gnu.org...done
Getting PWD... [2 times]
Warning! Unable to get home directory
Getting PWD... [2 times]
Entering debugger...
Mark set [2 times]
Back to top level.
Mark set

Load-path shadows:
None found.

Features:
(shadow sort mail-extr message rfc822 mml mml-sec mm-decode mm-bodies
mm-encode mail-parse rfc2231 rfc2047 rfc2045 ietf-drums mailabbrev
mail-utils gmm-utils mailheader emacsbug url-util url-parse url-vars
help-mode easymenu view debug ange-ftp comint ring tramp-ftp tramp
tramp-compat auth-source eieio byte-opt bytecomp byte-compile assoc
gnus-util time-date mm-util mail-prsvr password-cache format-spec advice
help-fns advice-preload tramp-loaddefs dired regexp-opt tooltip
ediff-hook vc-hooks lisp-float-type mwheel ns-win tool-bar dnd fontset
image fringe lisp-mode register page menu-bar rfn-eshadow timer select
scroll-bar mouse jit-lock font-lock syntax facemenu font-core frame cham
georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao
korean japanese hebrew greek romanian slovak czech european ethiopic
indian cyrillic chinese case-table epa-hook jka-cmpr-hook help simple
abbrev loaddefs button minibuffer faces cus-face files text-properties
overlay md5 base64 format env code-pages mule custom widget
hashtable-print-readable backquote make-network-process ns multi-tty
emacs)