23.0.50; w32-shell-execute and Swedish =8f6

["Lennart Borgman (gmail)" <lennart.borgman@gmail.com>]

When I try to use w32-shell-execute to get Windows Explorer to show a 
file's folder with the file selected this fails if there is with a 
Swedish o with two dots above it in the file name. Otherwise it 
succeeds. When it fails I get message box (from Windows Explorer) saying 
something like

    The path 'file-path-with-Swedish-o-with-dots.txt' does not
    exist or is not a directory.

The o with dots in this case gives the following output when I do C-u C-x =

==========================================================
   character: ö (2294, #o4366, #x8f6, U+00F6)
     charset: latin-iso8859-1 (Right-Hand Part of Latin Alphabet 1 
(ISO/IEC 8859-1): ISO-IR-100.)
  code point: #x76
      syntax: w 	which means: word
    category: l:Latin
buffer code: #x81 #xF6
   file code: not encodable by coding system undecided-dos
     display: by this font (glyph code)
      -outline-Courier 
New-normal-r-normal-normal-13-97-96-96-c-*-iso8859-1 (#xF6)

There is an overlay here:
  From 12 to 30
   evaporate            nil
   face                 viper-minibuffer-vi
   priority             300

[back]
==========================================================

To reproduce the problemi start emacs with

    emacs -Q

Compile these functions in the *scratch* buffer

(defun w32shell-explorer-file (file)
   "Open Windows Explorer with file FILE selected."
   (interactive "fFile to focus in Explorer: ")
   (let ((full-file (expand-file-name file)))
     (setq full-file (replace-regexp-in-string "/" "\\" full-file t t))
     (w32-shell-execute nil (concat (getenv "SystemRoot") "\\explorer.exe")
                        (concat "/n,/select," full-file))))

(defun w32shell-explorer-current-file ()
   "Open Windows Explorer with current file selected."
   (interactive)
   (if buffer-file-name
       (w32shell-explorer-file buffer-file-name)
     (message "Buffer has no file name")))

Create a file with the char above in its name and open it in Emacs. Now do

   M-x w32shell-explorer-current-file RET



In GNU Emacs 23.0.50.1 (i386-mingw-nt5.1.2600)
  of 2008-01-21 on LENNART-69DE564
Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (3.4) --cflags -Ic:/g/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
   locale-coding-system: cp1252
   default-enable-multibyte-characters: t

Major mode: Text

Minor modes in effect:
   tooltip-mode: t
   tool-bar-mode: t
   mouse-wheel-mode: t
   menu-bar-mode: t
   file-name-shadow-mode: t
   global-font-lock-mode: t
   font-lock-mode: t
   blink-cursor-mode: t
   unify-8859-on-encoding-mode: t
   utf-translate-cjk-mode: t
   auto-compression-mode: t
   line-number-mode: t

Recent input:
C-x C-f s <tab> <return> C-x b * s <tab> <return> <help-echo>
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo>
<help-echo> <help-echo> <help-echo> M-x v i p e r -
m o d e <return> p M-x e v a l - b u f f e r <return>
C-x b <return> M-x w 3 2 - s h <tab> <backspace> <backspace>
<backspace> h <backspace> s h <tab> <return> C-x b
<return> <down> <down> <down> <down> <down> <down>
<up> <up> <up> <up> <up> <up> <up> <up> <up> <up> p
M-x <up> <up> <return> C-x b <return> M-x w 3 2 s h
<tab> <tab> c u <tab> <return> <help-echo> <help-echo>
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo>
<help-echo> <help-echo> <help-echo> <menu-bar> <help-menu>
<send-emacs-bug-report>

Recent messages:
Warning: no fonts matching `-*-dejavu sans 
mono-normal-r-normal-*-13-*-*-*-c-*-iso8859-1' available [2 times]
Warning: no fonts matching 
`-*-opensymbol-normal-r-normal-*-12-*-*-*-c-*-iso8859-1' available [2 times]
For information about GNU Emacs and the GNU system, type C-h C-a.
Loading viper...
Loading c:/Documents and Settings/Lennart Borgman/Application 
Data/.viper...done
Loading viper...done
Inserted 224 character(s), 6 line(s)
if: Symbol's function definition is void: w32shell-explorer-file
Inserted 379 character(s), 8 line(s)
Making completion list...