(detect_coding_iso2022): Do not exclude posibility of

7-bit encoding when designation to G1 occurs.  If CSI, SS2, or SS3
is found, return CODING_CATEGORY_MASK_ISO_8_ELSE.
(Fdetect_coding_region): Doc-string modified.

diff --git a/src/coding.c b/src/coding.c
index 5bfcacc1e177f529e36a9ec947aabba105f2f14f..ee5fdf25fc2fbf4aac2a34082de819957ee842bf 100644 (file)
--- a/src/coding.c
+++ b/src/coding.c
@@ -623,38 +623,59 @@ detect_coding_iso2022 (src, src_end)
          if (src >= src_end)
            break;
          c = *src++;
-         if (src < src_end
-             && ((c >= '(' && c <= '/')
-                 || c == '$' && ((*src >= '(' && *src <= '/')
-                                 || (*src >= '@' && *src <= 'B'))))
+         if ((c >= '(' && c <= '/'))
            {
-             /* Valid designation sequence.  */
-             if (c == ')' || (c == '$' && *src == ')'))
+             /* Designation sequence for a charset of dimension 1.  */
+             if (src >= src_end)
+               break;
+             c = *src++;
+             if (c < ' ' || c >= 0x80)
+               /* Invalid designation sequence.  */
+               return 0;
+           }
+         else if (c == '$')
+           {
+             /* Designation sequence for a charset of dimension 2.  */
+             if (src >= src_end)
+               break;
+             c = *src++;
+             if (c >= '@' && c <= 'B')
+               /* Designation for JISX0208.1978, GB2312, or JISX0208.  */
+               ;
+             else if (c >= '(' && c <= '/')
                {
-                 g1 = 1;
-                 mask &= ~(CODING_CATEGORY_MASK_ISO_7
-                           | CODING_CATEGORY_MASK_ISO_7_ELSE);
+                 if (src >= src_end)
+                   break;
+                 c = *src++;
+                 if (c < ' ' || c >= 0x80)
+                   /* Invalid designation sequence.  */
+                   return 0;
                }
-             src++;
-             break;
+             else
+               /* Invalid designation sequence.  */
+               return 0;
            }
          else if (c == 'N' || c == 'O' || c == 'n' || c == 'o')
+           /* Locking shift.  */
            mask &= (CODING_CATEGORY_MASK_ISO_7_ELSE
                     | CODING_CATEGORY_MASK_ISO_8_ELSE);
+         else if (c == '0' || c == '1' || c == '2')
+           /* Start/end composition.  */
+           ;
+         else
+           /* Invalid escape sequence.  */
+           return 0;
          break;
 
        case ISO_CODE_SO:
-         if (g1)
-           mask &= (CODING_CATEGORY_MASK_ISO_7_ELSE
-                    | CODING_CATEGORY_MASK_ISO_8_ELSE);
+         mask &= (CODING_CATEGORY_MASK_ISO_7_ELSE
+                  | CODING_CATEGORY_MASK_ISO_8_ELSE);
          break;
          
        case ISO_CODE_CSI:
        case ISO_CODE_SS2:
        case ISO_CODE_SS3:
-         mask &= ~(CODING_CATEGORY_MASK_ISO_7
-                   | CODING_CATEGORY_MASK_ISO_7_ELSE);
-         break;
+         return CODING_CATEGORY_MASK_ISO_8_ELSE;
 
        default:
          if (c < 0x80)
@@ -3001,10 +3022,10 @@ The value of property should be a vector of length 5.")
 
 DEFUN ("detect-coding-region", Fdetect_coding_region, Sdetect_coding_region,
        2, 2, 0,
-  "Detect coding-system of the text in the region between START and END.\n\
-Return a list of possible coding-systems ordered by priority.\n\
+  "Detect coding system of the text in the region between START and END.\n\
+Return a list of possible coding systems ordered by priority.\n\
 If only ASCII characters are found, it returns `undecided'\n\
- or its subsidiary coding-system according to a detected end-of-line format.")
+ or its subsidiary coding system according to a detected end-of-line format.")
   (b, e)
      Lisp_Object b, e;
 {