[Emacs-diffs] emacs-25 5878abf: Fix 'expand-file-name' during startup on MS-Windows

[Eli Zaretskii]

branch: emacs-25
commit 5878abf87b6b3ead1367cbae5cc6b0743349f611
Author: Eli Zaretskii <address@hidden>
Commit: Eli Zaretskii <address@hidden>

    Fix 'expand-file-name' during startup on MS-Windows
    
    * src/w32.c (w32_init_file_name_codepage): New function, resets
    file_name_codepage and w32_ansi_code_page to undo the values
    recorded during dumping.
    (codepage_for_filenames): Fix an embarrassing typo.  Ignore the
    cached value of file-name encoding if it is nil, i.e. not
    initialized yet.  Actually cache the last used file-name encoding
    to avoid calling APIs when not necessary.
    
    * src/w32.h (w32_init_file_name_codepage): Add prototype.
    
    * src/w32term.c (syms_of_w32term): Set the value of
    w32_unicode_filenames according to the OS version.  This avoids
    resetting it during startup, which then causes temacs to run with
    the incorrect value.
    
    * src/emacs.c (main): Call w32_init_file_name_codepage early
    during the startup.
    
    * src/fileio.c (Fexpand_file_name) [WINDOWSNT]: Update 'newdir'
    after converting $HOME to a UTF-8 string, so that 'newdirlim' is
    consistent with it.  (Bug#25038)
    
    * lisp/international/mule-cmds.el (set-locale-environment): Set
    'default-file-name-coding-system' to the ANSI codepage even in
    non-interactive sessions.
    
    * lisp/files.el (directory-abbrev-alist, abbreviated-home-dir):
    Doc fix.
    (abbreviate-file-name): Decode 'abbreviated-home-dir' if it is a
    unibyte string.
    
    * doc/lispref/files.texi (Directory Names): Index
    'directory-abbrev-alist'.
---
 doc/lispref/files.texi          |    1 +
 lisp/files.el                   |   39 ++++++++++++++++++++++++++++-----------
 lisp/international/mule-cmds.el |   12 +++++++-----
 src/emacs.c                     |    3 +++
 src/fileio.c                    |    8 ++++----
 src/w32.c                       |   18 ++++++++++++++++--
 src/w32.h                       |    1 +
 src/w32term.c                   |    5 ++++-
 8 files changed, 64 insertions(+), 23 deletions(-)

diff --git a/doc/lispref/files.texi b/doc/lispref/files.texi
index 544992d..85c80d7 100644
--- a/doc/lispref/files.texi
+++ b/doc/lispref/files.texi
@@ -2151,6 +2151,7 @@ function:
 
 @cindex file name abbreviations
 @cindex abbreviated file names
address@hidden directory-abbrev-alist
 @defun abbreviate-file-name filename
 @anchor{abbreviate-file-name}
 This function returns an abbreviated form of @var{filename}.  It
diff --git a/lisp/files.el b/lisp/files.el
index fa63073..45646b1 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -51,20 +51,21 @@ when it has unsaved changes."
   nil
   "Alist of abbreviations for file directories.
 A list of elements of the form (FROM . TO), each meaning to replace
-FROM with TO when it appears in a directory name.  This replacement is
-done when setting up the default directory of a newly visited file.
+a match for FROM with TO when a directory name matches FROM.  This
+replacement is done when setting up the default directory of a
+newly visited file buffer.
 
-FROM is matched against directory names anchored at the first
-character, so it should start with a \"\\\\\\=`\", or, if directory
-names cannot have embedded newlines, with a \"^\".
+FROM is a regexp that is matched against directory names anchored at
+the first character, so it should start with a \"\\\\\\=`\", or, if
+directory names cannot have embedded newlines, with a \"^\".
 
 FROM and TO should be equivalent names, which refer to the
-same directory.  Do not use `~' in the TO strings;
-they should be ordinary absolute directory names.
+same directory.  TO should be an absolute directory name.
+Do not use `~' in the TO strings.
 
 Use this feature when you have directories which you normally refer to
 via absolute symbolic links.  Make TO the name of the link, and FROM
-the name it is linked to."
+a regexp matching the name it is linked to."
   :type '(repeat (cons :format "%v"
                       :value ("\\`" . "")
                       (regexp :tag "From")
@@ -1736,7 +1737,8 @@ Choose the buffer's name using 
`generate-new-buffer-name'."
 (make-obsolete-variable 'automount-dir-prefix 'directory-abbrev-alist "24.3")
 
 (defvar abbreviated-home-dir nil
-  "The user's homedir abbreviated according to `directory-abbrev-alist'.")
+  "Regexp matching the user's homedir at the beginning of file name.
+The value includes abbreviation according to `directory-abbrev-alist'.")
 
 (defun abbreviate-file-name (filename)
   "Return a version of FILENAME shortened using `directory-abbrev-alist'.
@@ -1770,8 +1772,23 @@ home directory is a root directory) and removes 
automounter prefixes
       (or abbreviated-home-dir
          (setq abbreviated-home-dir
                (let ((abbreviated-home-dir "$foo"))
-                 (concat "\\`" (abbreviate-file-name (expand-file-name "~"))
-                         "\\(/\\|\\'\\)"))))
+                  (setq abbreviated-home-dir
+                        (concat "\\`"
+                                (abbreviate-file-name (expand-file-name "~"))
+                                "\\(/\\|\\'\\)"))
+                  ;; Depending on whether default-directory does or
+                  ;; doesn't include non-ASCII characters, the value
+                  ;; of abbreviated-home-dir could be multibyte or
+                  ;; unibyte.  In the latter case, we need to decode
+                  ;; it.  Note that this function is called for the
+                  ;; first time (from startup.el) when
+                  ;; locale-coding-system is already set up.
+                  (if (multibyte-string-p abbreviated-home-dir)
+                      abbreviated-home-dir
+                    (decode-coding-string abbreviated-home-dir
+                                          (if (eq system-type 'windows-nt)
+                                              'utf-8
+                                            locale-coding-system))))))
 
       ;; If FILENAME starts with the abbreviated homedir,
       ;; make it start with `~' instead.
diff --git a/lisp/international/mule-cmds.el b/lisp/international/mule-cmds.el
index 5008fd5..1ec7456 100644
--- a/lisp/international/mule-cmds.el
+++ b/lisp/international/mule-cmds.el
@@ -2704,10 +2704,12 @@ See also `locale-charset-language-names', 
`locale-language-names',
     ;; terminal-coding-system with the ANSI or console codepage.
     (when (and (eq system-type 'windows-nt)
                (boundp 'w32-ansi-code-page))
-      (let* ((code-page-coding
-              (intern (format "cp%d" (if noninteractive
-                                         (w32-get-console-codepage)
-                                       w32-ansi-code-page))))
+      (let* ((ansi-code-page-coding
+              (intern (format "cp%d" w32-ansi-code-page)))
+             (code-page-coding
+              (if noninteractive
+                  (intern (format "cp%d" (w32-get-console-codepage)))
+                ansi-code-page-coding))
              (output-coding
               (if noninteractive
                   (intern (format "cp%d" (w32-get-console-output-codepage)))
@@ -2717,7 +2719,7 @@ See also `locale-charset-language-names', 
`locale-language-names',
          (unless frame (setq locale-coding-system code-page-coding))
          (set-keyboard-coding-system code-page-coding frame)
          (set-terminal-coding-system output-coding frame)
-         (setq default-file-name-coding-system code-page-coding))))
+         (setq default-file-name-coding-system ansi-code-page-coding))))
 
     (when (eq system-type 'darwin)
       ;; On Darwin, file names are always encoded in utf-8, no matter
diff --git a/src/emacs.c b/src/emacs.c
index ce30ae7..16cf6cc 100644
--- a/src/emacs.c
+++ b/src/emacs.c
@@ -716,6 +716,9 @@ main (int argc, char **argv)
      to have non-stub implementations of APIs we need to convert file
      names between UTF-8 and the system's ANSI codepage.  */
   maybe_load_unicows_dll ();
+  /* Initialize the codepage for file names, needed to decode
+     non-ASCII file names during startup.  */
+  w32_init_file_name_codepage ();
 #endif
   /* This has to be done before module_init is called below, so that
      the latter could use the thread ID of the main thread.  */
diff --git a/src/fileio.c b/src/fileio.c
index c3b2be7..d94805f 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -1063,8 +1063,6 @@ filesystem tree, not (expand-file-name ".."  dirname).  
*/)
          if (!(newdir = egetenv ("HOME")))
            newdir = newdirlim = "";
          nm++;
-         /* `egetenv' may return a unibyte string, which will bite us since
-            we expect the directory to be multibyte.  */
 #ifdef WINDOWSNT
          if (newdir[0])
            {
@@ -1072,11 +1070,14 @@ filesystem tree, not (expand-file-name ".."  dirname).  
*/)
 
              filename_from_ansi (newdir, newdir_utf8);
              tem = make_unibyte_string (newdir_utf8, strlen (newdir_utf8));
+             newdir = SSDATA (tem);
            }
          else
 #endif
            tem = build_string (newdir);
          newdirlim = newdir + SBYTES (tem);
+         /* `egetenv' may return a unibyte string, which will bite us
+            if we expect the directory to be multibyte.  */
          if (multibyte && !STRING_MULTIBYTE (tem))
            {
              hdir = DECODE_FILE (tem);
@@ -1105,8 +1106,7 @@ filesystem tree, not (expand-file-name ".."  dirname).  
*/)
 
              newdir = pw->pw_dir;
              /* `getpwnam' may return a unibyte string, which will
-                bite us since we expect the directory to be
-                multibyte.  */
+                bite us when we expect the directory to be multibyte.  */
              tem = make_unibyte_string (newdir, strlen (newdir));
              newdirlim = newdir + SBYTES (tem);
              if (multibyte && !STRING_MULTIBYTE (tem))
diff --git a/src/w32.c b/src/w32.c
index 793bc0f..7c57693 100644
--- a/src/w32.c
+++ b/src/w32.c
@@ -1493,6 +1493,16 @@ w32_valid_pointer_p (void *p, int size)
 /* Current codepage for encoding file names.  */
 static int file_name_codepage;
 
+/* Initialize the codepage used for decoding file names.  This is
+   needed to undo the value recorded during dumping, which might not
+   be correct when we run the dumped Emacs.  */
+void
+w32_init_file_name_codepage (void)
+{
+  file_name_codepage = CP_ACP;
+  w32_ansi_code_page = CP_ACP;
+}
+
 /* Produce a Windows ANSI codepage suitable for encoding file names.
    Return the information about that codepage in CP_INFO.  */
 int
@@ -1509,12 +1519,13 @@ codepage_for_filenames (CPINFO *cp_info)
   if (NILP (current_encoding))
     current_encoding = Vdefault_file_name_coding_system;
 
-  if (!EQ (last_file_name_encoding, current_encoding))
+  if (!EQ (last_file_name_encoding, current_encoding)
+      || NILP (last_file_name_encoding))
     {
       /* Default to the current ANSI codepage.  */
       file_name_codepage = w32_ansi_code_page;
 
-      if (NILP (current_encoding))
+      if (!NILP (current_encoding))
        {
          char *cpname = SSDATA (SYMBOL_NAME (current_encoding));
          char *cp = NULL, *end;
@@ -1543,6 +1554,9 @@ codepage_for_filenames (CPINFO *cp_info)
          if (!GetCPInfo (file_name_codepage, &cp))
            emacs_abort ();
        }
+
+      /* Cache the new value.  */
+      last_file_name_encoding = current_encoding;
     }
   if (cp_info)
     *cp_info = cp;
diff --git a/src/w32.h b/src/w32.h
index 42a1c42..08b88f5 100644
--- a/src/w32.h
+++ b/src/w32.h
@@ -195,6 +195,7 @@ extern int  filename_from_ansi (const char *, char *);
 extern int  filename_to_ansi (const char *, char *);
 extern int  filename_from_utf16 (const wchar_t *, char *);
 extern int  filename_to_utf16 (const char *, wchar_t *);
+extern void w32_init_file_name_codepage (void);
 extern int  codepage_for_filenames (CPINFO *);
 extern Lisp_Object ansi_encode_filename (Lisp_Object);
 extern int  w32_copy_file (const char *, const char *, int, int, int);
diff --git a/src/w32term.c b/src/w32term.c
index 51743f8..7b74ae0 100644
--- a/src/w32term.c
+++ b/src/w32term.c
@@ -7157,7 +7157,10 @@ specified by `file-name-coding-system'.
 This variable is set to non-nil by default when Emacs runs on Windows
 systems of the NT family, including W2K, XP, Vista, Windows 7 and
 Windows 8.  It is set to nil on Windows 9X.  */);
-  w32_unicode_filenames = 0;
+  if (os_subtype == OS_9X)
+    w32_unicode_filenames = 0;
+  else
+    w32_unicode_filenames = 1;
 
 
   /* FIXME: The following variable will be (hopefully) removed