(skip_chars): Use INC_POS instead of INC_BOTH.

(Fforward_comment): Always use both FROM and FROM_BYTE to set point.
Use dec_bytepos not DEC_POS.
(scan_lists): Handle unibyte buffers when decrementing temp_pos.
(INC_FROM): Use INC_BOTH.
(inc_bytepos, dec_bytepos): In unibyte mode, just increment bytepos.

1 files changed, 36 insertions, 34 deletions

diff --git a/src/syntax.c b/src/syntax.c
index 9f0495401dc..68ef32828c4 100644
--- a/src/syntax.c
+++ b/src/syntax.c
@@ -294,6 +294,9 @@ INLINE int
 inc_bytepos (bytepos)
      int bytepos;
 {
+  if (NILP (current_buffer->enable_multibyte_characters))
+    return bytepos + 1;
+
   INC_POS (bytepos);
   return bytepos;
 }
@@ -305,6 +308,9 @@ INLINE int
 dec_bytepos (bytepos)
      int bytepos;
 {
+  if (NILP (current_buffer->enable_multibyte_characters))
+    return bytepos - 1;
+
   DEC_POS (bytepos);
   return bytepos;
 }
@@ -1367,7 +1373,10 @@ skip_chars (forwardp, syntaxp, string, lim)
                 while (pos < XINT (lim)
                        && fastmap[(int) SYNTAX (FETCH_CHAR (pos_byte))])
                   {
-                    INC_BOTH (pos, pos_byte);
+                    /* Since we already checked for multibyteness,
+                       avoid using INC_BOTH which checks again.  */
+                    INC_POS (pos_byte);
+                    pos++;
                     UPDATE_SYNTAX_TABLE_FORWARD (pos);
                   }
               }
@@ -1388,7 +1397,10 @@ skip_chars (forwardp, syntaxp, string, lim)
                 while (pos > XINT (lim))
                   {
                     int savepos = pos_byte;
-                    DEC_BOTH (pos, pos_byte);
+                    /* Since we already checked for multibyteness,
+                       avoid using DEC_BOTH which checks again.  */
+                    pos--;
+                    DEC_POS (pos_byte);
                     UPDATE_SYNTAX_TABLE_BACKWARD (pos);
                     if (!fastmap[(int) SYNTAX (FETCH_CHAR (pos_byte))])
                       {
@@ -1547,10 +1559,7 @@ between them, return t; otherwise return nil.")
         {
           if (from == stop)
             {
-              if (! NILP (current_buffer->enable_multibyte_characters))
-                SET_PT_BOTH (from, from_byte);
-              else
-                SET_PT_BOTH (from_byte, from_byte);
+              SET_PT_BOTH (from, from_byte);
               immediate_quit = 0;
               return Qnil;
             }
@@ -1579,10 +1588,7 @@ between them, return t; otherwise return nil.")
         {
           immediate_quit = 0;
           DEC_BOTH (from, from_byte);
-          if (! NILP (current_buffer->enable_multibyte_characters))
-            SET_PT_BOTH (from, from_byte);
-          else
-            SET_PT_BOTH (from_byte, from_byte);
+          SET_PT_BOTH (from, from_byte);
           return Qnil;
         }
       /* We're at the start of a comment.  */
@@ -1591,10 +1597,7 @@ between them, return t; otherwise return nil.")
           if (from == stop)
             {
               immediate_quit = 0;
-              if (! NILP (current_buffer->enable_multibyte_characters))
-                SET_PT_BOTH (from, from_byte);
-              else
-                SET_PT_BOTH (from_byte, from_byte);
+              SET_PT_BOTH (from, from_byte);
               return Qnil;
             }
           UPDATE_SYNTAX_TABLE_FORWARD (from);
@@ -1653,8 +1656,7 @@ between them, return t; otherwise return nil.")
           comstyle = 0;
           if (code == Sendcomment)
             comstyle = SYNTAX_COMMENT_STYLE (c);
-          temp_pos = from_byte;
-          DEC_POS (temp_pos);
+          temp_pos = dec_bytepos (from_byte);
           if (from > stop && SYNTAX_COMEND_SECOND (c)
               && (c1 = FETCH_CHAR (temp_pos),
                   SYNTAX_COMEND_FIRST (c1))
@@ -1719,10 +1721,7 @@ between them, return t; otherwise return nil.")
             leave:
               immediate_quit = 0;
               INC_BOTH (from, from_byte);
-              if (! NILP (current_buffer->enable_multibyte_characters))
-                SET_PT_BOTH (from, from_byte);
-              else
-                SET_PT_BOTH (from_byte, from_byte);
+              SET_PT_BOTH (from, from_byte);
               return Qnil;
             }
         }
@@ -1730,10 +1729,7 @@ between them, return t; otherwise return nil.")
       count1++;
     }
 
-  if (! NILP (current_buffer->enable_multibyte_characters))
-    SET_PT_BOTH (from, from_byte);
-  else
-    SET_PT_BOTH (from_byte, from_byte);
+  SET_PT_BOTH (from, from_byte);
   immediate_quit = 0;
   return Qt;
 }
@@ -1891,8 +1887,7 @@ scan_lists (from, count, depth, sexpflag)
 
             case Sstring:
             case Sstring_fence:
-              temp_pos = from_byte;
-              DEC_POS (temp_pos);
+              temp_pos = dec_bytepos (from_byte);
               stringterm = FETCH_CHAR (temp_pos);
               while (1)
                 {
@@ -1941,7 +1936,10 @@ scan_lists (from, count, depth, sexpflag)
           if (code == Sendcomment)
             comstyle = SYNTAX_COMMENT_STYLE (c);
           temp_pos = from_byte;
-          DEC_POS (temp_pos);
+          if (! NILP (current_buffer->enable_multibyte_characters))
+            DEC_POS (temp_pos);
+          else
+            temp_pos--;
           if (from > stop && SYNTAX_COMEND_SECOND (c)
               && (c1 = FETCH_CHAR (temp_pos), SYNTAX_COMEND_FIRST (c1))
               && parse_sexp_ignore_comments)
@@ -1973,7 +1971,10 @@ scan_lists (from, count, depth, sexpflag)
               while (from > stop)
                 {
                   temp_pos = from_byte;
-                  DEC_POS (temp_pos);
+                  if (! NILP (current_buffer->enable_multibyte_characters))
+                    DEC_POS (temp_pos);
+                  else
+                    temp_pos--;
                   UPDATE_SYNTAX_TABLE_BACKWARD (from - 1);
                   c1 = FETCH_CHAR (temp_pos);
                   temp_code = SYNTAX (c1);
@@ -1984,7 +1985,7 @@ scan_lists (from, count, depth, sexpflag)
                   if (quoted)
                     {
                       DEC_BOTH (from, from_byte);
-                      DEC_POS (temp_pos);
+                      temp_pos = dec_bytepos (temp_pos);
                       UPDATE_SYNTAX_TABLE_BACKWARD (from - 1);
                     }
                   c1 = FETCH_CHAR (temp_pos);
@@ -2000,8 +2001,7 @@ scan_lists (from, count, depth, sexpflag)
             case Smath:
               if (!sexpflag)
                 break;
-              temp_pos = from_byte;
-              DEC_POS (temp_pos);
+              temp_pos = dec_bytepos (from_byte);
               UPDATE_SYNTAX_TABLE_BACKWARD (from - 1);
               if (from != stop && c == FETCH_CHAR (temp_pos))
                 DEC_BOTH (from, from_byte);
@@ -2055,7 +2055,10 @@ scan_lists (from, count, depth, sexpflag)
                 {
                   if (from == stop) goto lose;
                   temp_pos = from_byte;
-                  DEC_POS (temp_pos);
+                  if (! NILP (current_buffer->enable_multibyte_characters))
+                    DEC_POS (temp_pos);
+                  else
+                    temp_pos--;
                   UPDATE_SYNTAX_TABLE_BACKWARD (from - 1);
                   if (!char_quoted (from - 1, temp_pos)
                       && stringterm == FETCH_CHAR (temp_pos))
@@ -2214,8 +2217,7 @@ scan_sexps_forward (stateptr, from, from_byte, end, targetdepth,
 #define INC_FROM                                \
 do { prev_from = from;                          \
      prev_from_byte = from_byte;                \
-     from++;                                    \
-     INC_POS (from_byte);                       \
+     INC_BOTH (from, from_byte);                \
   } while (0)
 
   immediate_quit = 1;