(detect_coding_iso2022): Don't check the byte length of

succeeding codes (0xa0..0xFF) if the codes follows single shit
code.

1 files changed, 24 insertions, 8 deletions

diff --git a/src/coding.c b/src/coding.c
index 6b105b94a9c..9e6333f5878 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -683,7 +683,7 @@ detect_coding_iso2022 (src, src_end)
 {
   int mask = CODING_CATEGORY_MASK_ISO;
   int mask_found = 0;
-  int reg[4], shift_out = 0;
+  int reg[4], shift_out = 0, single_shifting = 0;
   int c, c1, i, charset;
 
   reg[0] = CHARSET_ASCII, reg[1] = reg[2] = reg[3] = -1;
@@ -693,6 +693,7 @@ detect_coding_iso2022 (src, src_end)
       switch (c)
         {
         case ISO_CODE_ESC:
+          single_shifting = 0;
           if (src >= src_end)
             break;
           c = *src++;
@@ -781,6 +782,7 @@ detect_coding_iso2022 (src, src_end)
           break;
 
         case ISO_CODE_SO:
+          single_shifting = 0;
           if (shift_out == 0
               && (reg[1] >= 0
                   || SHIFT_OUT_OK (CODING_CATEGORY_IDX_ISO_7_ELSE)
@@ -793,6 +795,7 @@ detect_coding_iso2022 (src, src_end)
           break;
           
         case ISO_CODE_SI:
+          single_shifting = 0;
           if (shift_out == 1)
             {
               /* Locking shift in.  */
@@ -802,6 +805,7 @@ detect_coding_iso2022 (src, src_end)
           break;
 
         case ISO_CODE_CSI:
+          single_shifting = 0;
         case ISO_CODE_SS2:
         case ISO_CODE_SS3:
           {
@@ -815,6 +819,7 @@ detect_coding_iso2022 (src, src_end)
                 if (coding_system_table[CODING_CATEGORY_IDX_ISO_8_2]->flags
                     & CODING_FLAG_ISO_SINGLE_SHIFT)
                   newmask |= CODING_CATEGORY_MASK_ISO_8_2;
+                single_shifting = 1;
               }
             if (VECTORP (Vlatin_extra_code_table)
                 && !NILP (XVECTOR (Vlatin_extra_code_table)->contents[c]))
@@ -833,9 +838,13 @@ detect_coding_iso2022 (src, src_end)
 
         default:
           if (c < 0x80)
-            break;
+            {
+              single_shifting = 0;
+              break;
+            }
           else if (c < 0xA0)
             {
+              single_shifting = 0;
               if (VECTORP (Vlatin_extra_code_table)
                   && !NILP (XVECTOR (Vlatin_extra_code_table)->contents[c]))
                 {
@@ -860,12 +869,19 @@ detect_coding_iso2022 (src, src_end)
               mask &= ~(CODING_CATEGORY_MASK_ISO_7BIT
                         | CODING_CATEGORY_MASK_ISO_7_ELSE);
               mask_found |= CODING_CATEGORY_MASK_ISO_8_1;
-              while (src < src_end && *src >= 0xA0)
-                src++;
-              if ((src - src_begin - 1) & 1 && src < src_end)
-                mask &= ~CODING_CATEGORY_MASK_ISO_8_2;
-              else
-                mask_found |= CODING_CATEGORY_MASK_ISO_8_2;
+              /* Check the length of succeeding codes of the range
+                 0xA0..0FF.  If the byte length is odd, we exclude
+                 CODING_CATEGORY_MASK_ISO_8_2.  We can check this only
+                 when we are not single shifting.  */
+              if (!single_shifting)
+                {
+                  while (src < src_end && *src >= 0xA0)
+                    src++;
+                  if ((src - src_begin - 1) & 1 && src < src_end)
+                    mask &= ~CODING_CATEGORY_MASK_ISO_8_2;
+                  else
+                    mask_found |= CODING_CATEGORY_MASK_ISO_8_2;
+                }
             }
           break;
         }