Finished conversion routines; w32-unicode-filenames exposed to Lisp.

5 files changed, 178 insertions, 78 deletions

diff --git a/src/coding.c b/src/coding.c
index ac828a48683..69b01553e7f 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -9473,6 +9473,49 @@ code_convert_string_norecord (Lisp_Object string, Lisp_Object coding_system,
   return code_convert_string (string, coding_system, Qt, encodep, 0, 1);
 }
 
+/* Encode or decode a file name, to or from a unibyte string suitable
+   for passing to C library functions.  */
+Lisp_Object
+decode_file_name (Lisp_Object fname)
+{
+#ifdef WINDOWSNT
+  /* The w32 build pretends to use UTF-8 for file-name encoding, and
+     converts the file names either to UTF-16LE or to the system ANSI
+     codepage internally, depending on the underlying OS; see w32.c.  */
+  if (! NILP (Fcoding_system_p (Qutf_8)))
+    return code_convert_string_norecord (fname, Qutf_8, 0);
+  return fname;
+#else  /* !WINDOWSNT */
+  if (! NILP (Vfile_name_coding_system))
+    return code_convert_string_norecord (fname, Vfile_name_coding_system, 0);
+  else if (! NILP (Vdefault_file_name_coding_system))
+    return code_convert_string_norecord (fname,
+                                         Vdefault_file_name_coding_system, 0);
+  else
+    return fname;
+#endif
+}
+
+Lisp_Object
+encode_file_name (Lisp_Object fname)
+{
+#ifdef WINDOWSNT
+  /* The w32 build pretends to use UTF-8 for file-name encoding, and
+     converts the file names either to UTF-16LE or to the system ANSI
+     codepage internally, depending on the underlying OS; see w32.c.  */
+  if (! NILP (Fcoding_system_p (Qutf_8)))
+    return code_convert_string_norecord (fname, Qutf_8, 1);
+  return fname;
+#else  /* !WINDOWSNT */
+  if (! NILP (Vfile_name_coding_system))
+    return code_convert_string_norecord (fname, Vfile_name_coding_system, 1);
+  else if (! NILP (Vdefault_file_name_coding_system))
+    return code_convert_string_norecord (fname,
+                                         Vdefault_file_name_coding_system, 1);
+  else
+    return fname;
+#endif
+}
 
 DEFUN ("decode-coding-string", Fdecode_coding_string, Sdecode_coding_string,
        2, 4, 0,
diff --git a/src/coding.h b/src/coding.h
index 0472bec99de..39f9d62462b 100644
--- a/src/coding.h
+++ b/src/coding.h
@@ -672,23 +672,11 @@ struct coding_system
 
 /* Encode the file name NAME using the specified coding system
    for file names, if any.  */
-#define ENCODE_FILE(name)                                                  \
-  (! NILP (Vfile_name_coding_system)                                       \
-   ? code_convert_string_norecord (name, Vfile_name_coding_system, 1)      \
-   : (! NILP (Vdefault_file_name_coding_system)                            \
-      ? code_convert_string_norecord (name, Vdefault_file_name_coding_system, 1) \
-      : name))
-
+#define ENCODE_FILE(NAME)  encode_file_name (NAME)
 
 /* Decode the file name NAME using the specified coding system
    for file names, if any.  */
-#define DECODE_FILE(name)                                                  \
-  (! NILP (Vfile_name_coding_system)                                       \
-   ? code_convert_string_norecord (name, Vfile_name_coding_system, 0)      \
-   : (! NILP (Vdefault_file_name_coding_system)                            \
-      ? code_convert_string_norecord (name, Vdefault_file_name_coding_system, 0) \
-      : name))
-
+#define DECODE_FILE(NAME)  decode_file_name (NAME)
 
 /* Encode the string STR using the specified coding system
    for system functions, if any.  */
@@ -716,6 +704,8 @@ extern Lisp_Object code_convert_string (Lisp_Object, Lisp_Object,
                                         Lisp_Object, bool, bool, bool);
 extern Lisp_Object code_convert_string_norecord (Lisp_Object, Lisp_Object,
                                                  bool);
+extern Lisp_Object encode_file_name (Lisp_Object);
+extern Lisp_Object decode_file_name (Lisp_Object);
 extern Lisp_Object raw_text_coding_system (Lisp_Object);
 extern Lisp_Object coding_inherit_eol_type (Lisp_Object, Lisp_Object);
 extern Lisp_Object complement_process_encoding_system (Lisp_Object);
diff --git a/src/w32.c b/src/w32.c
index 511cec15d5f..993d598ff54 100644
--- a/src/w32.c
+++ b/src/w32.c
@@ -300,8 +300,6 @@ static BOOL g_b_init_is_valid_security_descriptor;
 static BOOL g_b_init_set_file_security;
 static BOOL g_b_init_get_adapters_info;
 
-int w32_unicode_filenames;
-
 /*
   BEGIN: Wrapper functions around OpenProcessToken
   and other functions in advapi32.dll that are only
@@ -1186,12 +1184,74 @@ w32_valid_pointer_p (void *p, int size)
 
 
 
-/* Converting file names from UTF-8 to either UTF-16 or the system
-   ANSI codepage.  */
+/* Converting file names from UTF-8 to either UTF-16 or the ANSI
+   codepage defined by file-name-coding-system.  */
+
+/* Current codepage for encoding file names.  */
+static int file_name_codepage;
+
+/* Produce a Windows ANSI codepage suitable for encoding file names.
+   Return the information about that codepage in CP_INFO.  */
+static int
+codepage_for_filenames (CPINFO *cp_info)
+{
+  /* A simple cache to avoid calling GetCPInfo every time we need to
+     encode/decode a file name.  The file-name encoding is not
+     supposed to be changed too frequently, if ever.  */
+  static Lisp_Object last_file_name_encoding;
+  static CPINFO cp;
+  Lisp_Object current_encoding;
+
+  current_encoding = Vfile_name_coding_system;
+  if (NILP (current_encoding))
+    current_encoding = Vdefault_file_name_coding_system;
+
+  if (!EQ (last_file_name_encoding, current_encoding))
+    {
+      /* Default to the current ANSI codepage.  */
+      file_name_codepage = w32_ansi_code_page;
+
+      if (NILP (current_encoding))
+        {
+          char *cpname = SDATA (SYMBOL_NAME (current_encoding));
+          char *cp = NULL, *end;
+          int cpnum;
+
+          if (strncmp (cpname, "cp", 2) == 0)
+            cp = cpname + 2;
+          else if (strncmp (cpname, "windows-", 8) == 0)
+            cp = cpname + 8;
+
+          if (cp)
+            {
+              end = cp;
+              cpnum = strtol (cp, &end, 10);
+              if (cpnum && *end == '\0' && end - cp >= 2)
+                file_name_codepage = cpnum;
+            }
+        }
+
+      if (!file_name_codepage)
+        file_name_codepage = CP_ACP; /* CP_ACP = 0, but let's not assume that */
+
+      if (!GetCPInfo (file_name_codepage, &cp))
+        {
+          file_name_codepage = CP_ACP;
+          if (!GetCPInfo (file_name_codepage, &cp))
+            emacs_abort ();
+        }
+    }
+  if (cp_info)
+    *cp_info = cp;
+
+  return file_name_codepage;
+}
+
 static int
 filename_to_utf16 (const char *fn_in, wchar_t *fn_out)
 {
-  int result = MultiByteToWideChar (CP_UTF8, 0, fn_in, -1, fn_out, MAX_PATH);
+  int result = MultiByteToWideChar (CP_UTF8, MB_ERR_INVALID_CHARS, fn_in, -1,
+                                    fn_out, MAX_PATH);
 
   if (!result)
     {
@@ -1217,7 +1277,28 @@ filename_to_utf16 (const char *fn_in, wchar_t *fn_out)
 static int
 filename_from_utf16 (const wchar_t *fn_in, char *fn_out)
 {
-  return -1;
+  int result = WideCharToMultiByte (CP_UTF8, 0, fn_in, -1,
+                                    fn_out, MAX_UTF8_PATH, NULL, NULL);
+
+  if (!result)
+    {
+      DWORD err = GetLastError ();
+
+      switch (err)
+        {
+        case ERROR_INVALID_FLAGS:
+        case ERROR_INVALID_PARAMETER:
+          errno = EINVAL;
+          break;
+        case ERROR_INSUFFICIENT_BUFFER:
+        case ERROR_NO_UNICODE_TRANSLATION:
+        default:
+          errno = ENOENT;
+          break;
+        }
+      return -1;
+    }
+  return 0;
 }
 
 static int
@@ -1227,9 +1308,11 @@ filename_to_ansi (const char *fn_in, char *fn_out)
 
   if (filename_to_utf16 (fn_in, fn_utf16) == 0)
     {
-      int result = WideCharToMultiByte (CP_ACP, 0, fn_utf16, -1,
-                                        fn_out, MAX_UTF8_PATH, NULL, NULL);
+      int result;
+      int codepage = codepage_for_filenames (NULL);
 
+      result  = WideCharToMultiByte (codepage, 0, fn_utf16, -1,
+                                     fn_out, MAX_UTF8_PATH, NULL, NULL);
       if (!result)
         {
           DWORD err = GetLastError ();
@@ -1250,12 +1333,36 @@ filename_to_ansi (const char *fn_in, char *fn_out)
         }
       return 0;
     }
+  return -1;
 }
 
 static int
 filename_from_ansi (const char *fn_in, char *fn_out)
 {
-  return -1;
+  wchar_t fn_utf16[MAXPATHLEN];
+  int codepage = codepage_for_filenames (NULL);
+  int result = MultiByteToWideChar (codepage, MB_ERR_INVALID_CHARS, fn_in, -1,
+                                    fn_utf16, MAX_PATH);
+
+  if (!result)
+    {
+      DWORD err = GetLastError ();
+
+      switch (err)
+        {
+        case ERROR_INVALID_FLAGS:
+        case ERROR_INVALID_PARAMETER:
+          errno = EINVAL;
+          break;
+        case ERROR_INSUFFICIENT_BUFFER:
+        case ERROR_NO_UNICODE_TRANSLATION:
+        default:
+          errno = ENOENT;
+          break;
+        }
+      return -1;
+    }
+  return filename_from_utf16 (fn_utf16, fn_out);
 }
 
 
@@ -1662,66 +1769,16 @@ srandom (int seed)
   srand (seed);
 }
 
-/* Current codepage for encoding file names.  */
-static int file_name_codepage;
-
 /* Return the maximum length in bytes of a multibyte character
    sequence encoded in the current ANSI codepage.  This is required to
    correctly walk the encoded file names one character at a time.  */
 static int
 max_filename_mbslen (void)
 {
-  /* A simple cache to avoid calling GetCPInfo every time we need to
-     normalize a file name.  The file-name encoding is not supposed to
-     be changed too frequently, if ever.  */
-  static Lisp_Object last_file_name_encoding;
-  static int last_max_mbslen;
-  Lisp_Object current_encoding;
-
-  current_encoding = Vfile_name_coding_system;
-  if (NILP (current_encoding))
-    current_encoding = Vdefault_file_name_coding_system;
-
-  if (!EQ (last_file_name_encoding, current_encoding))
-    {
-      CPINFO cp_info;
-
-      last_file_name_encoding = current_encoding;
-      /* Default to the current ANSI codepage.  */
-      file_name_codepage = w32_ansi_code_page;
-      if (!NILP (current_encoding))
-        {
-          char *cpname = SDATA (SYMBOL_NAME (current_encoding));
-          char *cp = NULL, *end;
-          int cpnum;
-
-          if (strncmp (cpname, "cp", 2) == 0)
-            cp = cpname + 2;
-          else if (strncmp (cpname, "windows-", 8) == 0)
-            cp = cpname + 8;
-
-          if (cp)
-            {
-              end = cp;
-              cpnum = strtol (cp, &end, 10);
-              if (cpnum && *end == '\0' && end - cp >= 2)
-                file_name_codepage = cpnum;
-            }
-        }
-
-      if (!file_name_codepage)
-        file_name_codepage = CP_ACP; /* CP_ACP = 0, but let's not assume that */
-
-      if (!GetCPInfo (file_name_codepage, &cp_info))
-        {
-          file_name_codepage = CP_ACP;
-          if (!GetCPInfo (file_name_codepage, &cp_info))
-            emacs_abort ();
-        }
-      last_max_mbslen = cp_info.MaxCharSize;
-    }
+  CPINFO cp_info;
 
-  return last_max_mbslen;
+  codepage_for_filenames (&cp_info);
+  return cp_info.MaxCharSize;
 }
 
 /* Normalize filename by converting all path separators to
diff --git a/src/w32.h b/src/w32.h
index 32d0fdbe3cf..c836937bd66 100644
--- a/src/w32.h
+++ b/src/w32.h
@@ -200,8 +200,6 @@ extern void record_pending_deletion (char *);
 extern void sys_sleep (int);
 extern int sys_link (const char *, const char *);
 
-
-
 #ifdef HAVE_GNUTLS
 #include <gnutls/gnutls.h>
 
diff --git a/src/w32term.c b/src/w32term.c
index 8bc46734b7d..6c94090f3b7 100644
--- a/src/w32term.c
+++ b/src/w32term.c
@@ -6567,6 +6567,18 @@ X toolkit.  Possible values are: gtk, motif, xaw, or xaw3d.
 With MS Windows or Nextstep, the value is t.  */);
   Vx_toolkit_scroll_bars = Qt;
 
+  DEFVAR_BOOL ("w32-unicode-filenames",
+               w32_unicode_filenames,
+     doc: /* Non-nil means use Unicode APIs when passing file names to the OS.
+A value of nil means file names passed to the OS APIs and returned
+from those APIs are encoded/decoded using the ANSI codepage
+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;
+
   /* Tell Emacs about this window system.  */
   Fprovide (Qw32, Qnil);
 }