Avoid encoding file names run through dostounix_filename on MS-Windows.

 src/w32.c (normalize_filename): Accept an additional argument
 MULTIBYTE; if non-zero, traverse the file name by bytes and don't
 downcase it even if w32-downcase-file-names is non-nil.
 (dostounix_filename): Accept an additional argument MULTIBYTE and
 pass it to normalize_filename.
 (emacs_root_dir): Adjust.
 src/msdos.h (dostounix_filename): Adjust prototype.
 src/w32.h (dostounix_filename): Adjust prototype.
 src/msdos.c (dostounix_filename): Accept an additional argument and
 ignore it.
 (init_environment): Adjust callers of dostounix_filename.
 src/fileio.c (Ffile_name_directory, file_name_as_directory)
 (directory_file_name, Fexpand_file_name)
 (Fsubstitute_in_file_name): [DOS_NT] Adjust call to
 dostounix_filename.
 [WINDOWSNT]: Downcase file names if w32-downcase-file-names is
 non-nil.
 (Fsubstitute_in_file_name): [DOS_NT] Don't downcase environment
 variables, as egetenv is case-insensitive for DOS_NT.
 src/dired.c (file_name_completion): Don't call Fdirectory_file_name
 with an encoded file name.
 src/w32proc.c (Fw32_short_file_name, Fw32_long_file_name): Adjust
 calls to dostounix_filename.
 src/w32fns.c (Fx_file_dialog): Adjust call to dostounix_filename.
 src/unexw32.c (unexec): Adjust call to dostounix_filename.
 src/termcap.c (tgetent) [MSDOS]: Adjust call to dostounix_filename.
 src/emacs.c (decode_env_path) [DOS_NT]: Adjust call to
 dostounix_filename.
 src/callproc.c (Fcall_process) [MSDOS]: Adjust call to
 dostounix_filename.

1 files changed, 14 insertions, 7 deletions

diff --git a/src/w32.c b/src/w32.c
index 64e989a3b36..8b89bd3e660 100644
--- a/src/w32.c
+++ b/src/w32.c
@@ -1598,12 +1598,17 @@ max_filename_mbslen (void)
    case path name components to lower case.  */
 
 static void
-normalize_filename (register char *fp, char path_sep)
+normalize_filename (register char *fp, char path_sep, int multibyte)
 {
   char sep;
   char *elem, *p2;
   int dbcs_p = max_filename_mbslen () > 1;
 
+  /* Multibyte file names are in the Emacs internal representation, so
+     we can traverse them by bytes with no problems.  */
+  if (multibyte)
+    dbcs_p = 0;
+
   /* Always lower-case drive letters a-z, even if the filesystem
      preserves case in filenames.
      This is so filenames can be compared by string comparison
@@ -1620,7 +1625,7 @@ normalize_filename (register char *fp, char path_sep)
       fp += 2;
     }
 
-  if (NILP (Vw32_downcase_file_names))
+  if (multibyte || NILP (Vw32_downcase_file_names))
     {
       while (*fp)
 	{
@@ -1668,18 +1673,20 @@ normalize_filename (register char *fp, char path_sep)
   } while (*fp);
 }
 
-/* Destructively turn backslashes into slashes.  */
+/* Destructively turn backslashes into slashes.  MULTIBYTE non-zero
+   means the file name is a multibyte string in Emacs's internal
+   representation.  */
 void
-dostounix_filename (register char *p)
+dostounix_filename (register char *p, int multibyte)
 {
-  normalize_filename (p, '/');
+  normalize_filename (p, '/', multibyte);
 }
 
 /* Destructively turn slashes into backslashes.  */
 void
 unixtodos_filename (register char *p)
 {
-  normalize_filename (p, '\\');
+  normalize_filename (p, '\\', 0);
 }
 
 /* Remove all CR's that are followed by a LF.
@@ -2222,7 +2229,7 @@ emacs_root_dir (void)
     emacs_abort ();
   strcpy (root_dir, p);
   root_dir[parse_root (root_dir, NULL)] = '\0';
-  dostounix_filename (root_dir);
+  dostounix_filename (root_dir, 0);
   return root_dir;
 }