Use a system file's "character code" to set the encoding.

When reading a system file, use the "character code" as a
fallback to set the dictionary's character encoding.  If present,
record 7, subtype 20 will override this parameter.

diff --git a/src/data/sys-file-reader.c b/src/data/sys-file-reader.c
index fb4f6f93defcc8cc7486fd3039fe7a36f8efd37a..86607bcc91dbb4c2c523ac7d93cb5388fd53c82e 100644 (file)
--- a/src/data/sys-file-reader.c
+++ b/src/data/sys-file-reader.c
@@ -162,7 +162,9 @@ static void read_extension_record (struct sfm_reader *, struct dictionary *,
                                    struct sfm_read_info *);
 static void read_machine_integer_info (struct sfm_reader *,
                                        size_t size, size_t count,
-                                       struct sfm_read_info *);
+                                       struct sfm_read_info *,
+                                      struct dictionary *
+                                      );
 static void read_machine_float_info (struct sfm_reader *,
                                      size_t size, size_t count);
 static void read_display_parameters (struct sfm_reader *,
@@ -725,7 +727,7 @@ read_extension_record (struct sfm_reader *r, struct dictionary *dict,
   switch (subtype)
     {
     case 3:
-      read_machine_integer_info (r, size, count, info);
+      read_machine_integer_info (r, size, count, info, dict);
       return;
 
     case 4:
@@ -804,7 +806,8 @@ read_extension_record (struct sfm_reader *r, struct dictionary *dict,
 /* Read record type 7, subtype 3. */
 static void
 read_machine_integer_info (struct sfm_reader *r, size_t size, size_t count,
-                           struct sfm_read_info *info)
+                           struct sfm_read_info *info,
+                          struct dictionary *dict)
 {
   int version_major = read_int (r);
   int version_minor = read_int (r);
@@ -813,7 +816,7 @@ read_machine_integer_info (struct sfm_reader *r, size_t size, size_t count,
   int float_representation = read_int (r);
   int compression_code UNUSED = read_int (r);
   int integer_representation = read_int (r);
-  int character_code UNUSED = read_int (r);
+  int character_code = read_int (r);
 
   int expected_float_format;
   int expected_integer_format;
@@ -858,6 +861,47 @@ read_machine_integer_info (struct sfm_reader *r, size_t size, size_t count,
                 gettext (endian[integer_representation == 1]),
                 gettext (endian[expected_integer_format == 1]));
     }
+
+
+  /*
+    Record 7 (20) provides a much more reliable way of
+    setting the encoding.
+    The character_code is used as a fallback only.
+  */
+  if ( NULL == dict_get_encoding (dict))
+    {
+      switch (character_code)
+       {
+       case 1:
+         dict_set_encoding (dict, "EBCDIC-US");
+         break;
+       case 2:
+       case 3:
+         /* These ostensibly mean "7-bit ASCII" and "8-bit ASCII"[sic]
+            respectively.   However, there are known to be many files
+            in the wild with character code 2, yet have data which are
+            clearly not ascii.
+            Therefore we ignore these values.
+         */
+         return;
+       case 4:
+         dict_set_encoding (dict, "MS_KANJI");
+         break;
+       case 65000:
+         dict_set_encoding (dict, "UTF-7");
+         break;
+       case 65001:
+         dict_set_encoding (dict, "UTF-8");
+         break;
+       default:
+         {
+           char enc[100];
+           snprintf (enc, 100, "CP%d", character_code);
+           dict_set_encoding (dict, enc);
+         }
+         break;
+       };
+    }
 }
 
 /* Read record type 7, subtype 4. */