SEGFAULT using tramp in unicode emacs

[Michael Welsh Duggan]

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:

This emacs was built from the unicode branch, CVS updated 2007/07/27.

Starting with "emacs -Q":
I evaluated
(setq tramp-password-prompt-regexp
      "^.*\\(?:[pP]assword\\(?: for .*\\)?\\|passphrase.*\\):? *")

Note: The change to this regexp is no longer necessary, but ramins in
my .emacs from times past.

I then do `C-x C-f /spenser:/', where spenser is a machine which has
the following password prompt (without quotes, and changed to hide
user and machine details):

"Password for address@hidden: "

Output in messages is as follows:

Tramp: Opening connection for spenser using scp...
Tramp: Waiting 60s for local shell to come up...
Tramp: Sending command `ssh spenser   -e none && exit || exit'
Tramp: Waiting for prompts from remote shell
Tramp: Sending password
tramp-read-passwd: Wrong type argument: char-or-string-p, nil

I then do `M-x toggle-debug-on-error', kill the "*tramp/scp spenser*"
buffer, and attempt again.  I get the following backtrace:

  capitalize(nil)
  tramp-read-passwd(#<process *tramp/scp spenser*>)
  tramp-enter-password(#<process *tramp/scp spenser*>)
  tramp-action-password(#<process *tramp/scp spenser*> ["scp" nil "spenser" ""])
  tramp-process-one-action(#<process *tramp/scp spenser*> ["scp" nil "spenser" 
""] ((tramp-login-prompt-regexp tramp-action-login) 
(tramp-password-prompt-regexp tramp-action-password) (tramp-wrong-passwd-regexp 
tramp-action-permission-denied) (shell-prompt-pattern tramp-action-succeed) 
(tramp-shell-prompt-pattern tramp-action-succeed) (tramp-yesno-prompt-regexp 
tramp-action-yesno) (tramp-yn-prompt-regexp tramp-action-yn) 
(tramp-terminal-prompt-regexp tramp-action-terminal) 
(tramp-process-alive-regexp tramp-action-process-alive)))
  byte-code("...")
  byte-code("...")
  tramp-process-actions(#<process *tramp/scp spenser*> ["scp" nil "spenser" ""] 
((tramp-login-prompt-regexp tramp-action-login) (tramp-password-prompt-regexp 
tramp-action-password) (tramp-wrong-passwd-regexp 
tramp-action-permission-denied) (shell-prompt-pattern tramp-action-succeed) 
(tramp-shell-prompt-pattern tramp-action-succeed) (tramp-yesno-prompt-regexp 
tramp-action-yesno) (tramp-yn-prompt-regexp tramp-action-yn) 
(tramp-terminal-prompt-regexp tramp-action-terminal) 
(tramp-process-alive-regexp tramp-action-process-alive)) 60)
  tramp-maybe-open-connection(["scp" nil "spenser" ""])
  tramp-send-command(["scp" nil "spenser" ""] "cd ~; pwd")
  tramp-handle-expand-file-name("/spenser:" nil)
  apply(tramp-handle-expand-file-name ("/spenser:" nil))
  tramp-sh-file-name-handler(expand-file-name "/spenser:" nil)
  apply(tramp-sh-file-name-handler expand-file-name ("/spenser:" nil))
  tramp-file-name-handler(expand-file-name "/spenser:" nil)
  expand-file-name("/spenser:")
  find-file-noselect("/spenser:" nil nil t)
  find-file("/spenser:" t)
  call-interactively(find-file)

At this point, typing `M-x' causes a SIGSEGV.  Here are the relevant
backtraces:

txt4n8utrVaHs.txt
Description: bt full

txtofLoXqvJpY.txt
Description: xbacktrace

In GNU Emacs 23.0.0.8 (i686-pc-linux-gnu, X toolkit)
 of 2007-07-27 on maru
Windowing system distributor `The X.Org Foundation', version 11.0.10300000
configured using `configure  '--without-toolkit-scroll-bars' 
'--with-x-toolkit=lucid''

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

Major mode: Lisp Interaction

Minor modes in effect:
  display-time-mode: t
  shell-dirtrack-mode: t
  erc-autojoin-mode: t
  erc-button-mode: t
  erc-ring-mode: t
  erc-pcomplete-mode: t
  erc-track-mode: t
  erc-match-mode: t
  erc-fill-mode: t
  erc-stamp-mode: t
  erc-netsplit-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  global-auto-composition-mode: t
  auto-composition-mode: t
  auto-compression-mode: t
  line-number-mode: t

Recent input:
<help-echo> C-l <help-echo> <help-echo> M-x r e p o 
r t - e m <tab> <return>

Recent messages:
Loading cl-macs...done
Loading easymenu...done
Loading advice...done
Loading /home/md5i/src/elisp/nxml-mode/rng-auto.el (source)...done
Loading time...done [3 times]
Loading /home/md5i/.emacs-custom...done
Loading server...done
nil [2 times]
Loading emacsbug...done
goto-history-element: Beginning of history; no preceding item

-- 
Michael Welsh Duggan
(address@hidden)