bug#7210: 23.2; w32 emacsclient passes malformed -dir when run from a root directory

[Paul Du Bois]

This bug report will be sent to the Free Software Foundation,
not to your local site managers!
Please write in English if possible, because the Emacs maintainers
usually do not have translators to read other languages for them.

Your bug report will be posted to the bug-gnu-emacs@gnu.org mailing list,
and to the gnu.emacs.bug news group.

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug.  If you can, give
a recipe starting from `emacs -Q':

1. run emacs -q
2. load-library "server"
3. setq server-log t
4. M-x server-start

In a shell:

[c:\dfp-stack]emacsclient -V
emacsclient 23.2
[c:\dfp-stack]emacsclient -e nil
  *server* log shows:
  Wed Oct 13 16:35:06 2010 server <127.0.0.1:2260>: Received -auth
[elided] -dir c:\dfp-stack/ -current-frame -eval nil

[c:\dfp-stack]cd ..
[C:\]emacsclient -e nil
  *server* log shows:
Wed Oct 13 16:35:23 2010 server <127.0.0.1:2261>: Received -auth
[elided] -dir C:\/ -current-frame -eval nil

In a non-root directory (c:\dfp-stack) the -dir argument contains a
single trailing slash.  In a root directory (c:\) the -dir argument
contains two trailing slashes.

The user-visible symptom is that files edited in a root directory have
an incorrect absolute path, one that looks like a UNC path. It causes
emacs to hang while windows times out looking for a server.

For example:

[C:\dfp-stack]emacsclient -n P4CONFIG
Wed Oct 13 16:40:57 2010 server <127.0.0.1:2265>: New file:
c:/dfp-stack/P4CONFIG

[C:\]emacsclient -n foo
Wed Oct 13 16:14:30 2010 server <127.0.0.1:2205>: New file: //foo.txt

If Emacs crashed, and you have the Emacs process in the gdb debugger,
please include the output from the following gdb commands:
    `bt full' and `xbacktrace'.
For information about debugging Emacs, please read the file
c:/apps/emacs-23.2/etc/DEBUG.


In GNU Emacs 23.2.1 (i386-mingw-nt5.1.2600)
 of 2010-05-08 on G41R2F1
Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (3.4) --no-opt --cflags -Ic:/xpm/include'

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: ENU
  value of $XMODIFIERS: nil
  locale-coding-system: cp1252
  default enable-multibyte-characters: t

Major mode: Fundamental

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
  blink-cursor-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
M-( <return> C-x k <return> n C-x k <return> M-( l
o a d - l i b r a r y SPC " s e r v e r " C-e C-j M-(
s e t q SPC s e r v e r - l o g SPC t C-e C-j M-( s
e r v e r - s t a t <backspace> r t C-e C-j M-x s e
r v e r - s t a r t <return> <down-mouse-1> <mouse-1>
C-x b SPC s e r <tab> <return> <help-echo> <down-mouse-1>
<mouse-1> M-x r e p o r t - e m <tab> <return>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
insert-parentheses: Buffer is read-only: #<buffer *GNU Emacs*>
Preparing tutorial ...
Save your position in the tutorial? (y or n)
Tutorial position not saved
Loading server...done
Restarting server

Load-path shadows:
None found.

Features:
(shadow sort mail-extr message ecomplete rfc822 mml mml-sec
password-cache mm-decode mm-bodies mm-encode mailcap mail-parse rfc2231
rfc2047 rfc2045 qp ietf-drums mailabbrev nnheader gnus-util netrc
time-date mm-util mail-prsvr gmm-utils wid-edit mailheader canlock sha1
hex-util hashcash mail-utils emacsbug server tutorial help-mode easymenu
view tooltip ediff-hook vc-hooks lisp-float-type mwheel dos-w32
disp-table ls-lisp w32-win w32-vars tool-bar dnd fontset image fringe
lisp-mode register page menu-bar rfn-eshadow timer select scroll-bar
mldrag 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 multi-tty emacs)