1 files changed, 35 insertions, 17 deletions

diff --git a/src/syntax.c b/src/syntax.c
index 3b0289f41ad..9361ba05477 100644
--- a/src/syntax.c
+++ b/src/syntax.c
@@ -1348,12 +1348,34 @@ skip_chars (forwardp, syntaxp, string, lim)
   int multibyte = !NILP (current_buffer->enable_multibyte_characters);
   int string_multibyte;
   int size_byte;
+  unsigned char *str;
+  int len;
 
   CHECK_STRING (string, 0);
   char_ranges = (int *) alloca (XSTRING (string)->size * (sizeof (int)) * 2);
   string_multibyte = STRING_MULTIBYTE (string);
+  str = XSTRING (string)->data;
   size_byte = STRING_BYTES (XSTRING (string));
 
+  /* Adjust the multibyteness of the string to that of the buffer.  */
+  if (multibyte != string_multibyte)
+    {
+      int nbytes;
+
+      if (multibyte)
+        nbytes = count_size_as_multibyte (XSTRING (string)->data,
+                                          XSTRING (string)->size);
+      else
+        nbytes = XSTRING (string)->size;
+      if (nbytes != size_byte)
+        {
+          str = (unsigned char *) alloca (nbytes);
+          copy_text (XSTRING (string)->data, str, nbytes,
+                     string_multibyte, multibyte);
+          size_byte = nbytes;
+        }
+    }
+
   if (NILP (lim))
     XSETINT (lim, forwardp ? ZV : BEGV);
   else
@@ -1367,12 +1389,12 @@ skip_chars (forwardp, syntaxp, string, lim)
 
   bzero (fastmap, sizeof fastmap);
 
-  i = 0, i_byte = 0;
+  i_byte = 0;
 
   if (i_byte < size_byte
       && XSTRING (string)->data[0] == '^')
     {
-      negate = 1; i++, i_byte++;
+      negate = 1; i_byte++;
     }
 
   /* Find the characters specified and set their elements of fastmap.
@@ -1381,16 +1403,10 @@ skip_chars (forwardp, syntaxp, string, lim)
 
   while (i_byte < size_byte)
     {
-      int c_leading_code = XSTRING (string)->data[i_byte];
-
-      FETCH_STRING_CHAR_ADVANCE (c, string, i, i_byte);
+      int c_leading_code = str[i_byte];
 
-      /* Convert multibyteness between what the string has
-         and what the buffer has.  */
-      if (multibyte)
-        c = unibyte_char_to_multibyte (c);
-      else
-        c &= 0377;
+      c = STRING_CHAR_AND_LENGTH (str + i_byte, size_byte - i_byte, len);
+      i_byte += len;
 
       if (syntaxp)
         fastmap[syntax_spec_code[c & 0377]] = 1;
@@ -1401,23 +1417,25 @@ skip_chars (forwardp, syntaxp, string, lim)
               if (i_byte == size_byte)
                 break;
 
-              c_leading_code = XSTRING (string)->data[i_byte];
-              FETCH_STRING_CHAR_ADVANCE (c, string, i, i_byte);
+              c_leading_code = str[i_byte];
+              c = STRING_CHAR_AND_LENGTH (str+i_byte, size_byte-i_byte, len);
+              i_byte += len;
             }
           if (i_byte < size_byte
-              && XSTRING (string)->data[i_byte] == '-')
+              && str[i_byte] == '-')
             {
               unsigned int c2, c2_leading_code;
 
               /* Skip over the dash.  */
-              i++, i_byte++;
+              i_byte++;
 
               if (i_byte == size_byte)
                 break;
 
               /* Get the end of the range.  */
-              c2_leading_code = XSTRING (string)->data[i_byte];
-              FETCH_STRING_CHAR_ADVANCE (c2, string, i, i_byte);
+              c2_leading_code = str[i_byte];
+              c2 =STRING_CHAR_AND_LENGTH (str+i_byte, size_byte-i_byte, len);
+              i_byte += len;
 
               if (SINGLE_BYTE_CHAR_P (c))
                 {