1 files changed, 16 insertions, 19 deletions

diff --git a/src/regex.c b/src/regex.c
index 5cb997336f6..148100805eb 100644
--- a/src/regex.c
+++ b/src/regex.c
@@ -157,8 +157,9 @@
        {                                                                \
          re_char *dtemp = (p) == (str2) ? (end1) : (p);                 \
          re_char *dlimit = ((p) > (str2) && (p) <= (end2)) ? (str2) : (str1); \
-         while (dtemp-- > dlimit && !CHAR_HEAD_P (*dtemp));             \
-         c = STRING_CHAR (dtemp, (p) - dtemp);                          \
+         re_char *d0 = dtemp;                                           \
+         PREV_CHAR_BOUNDARY (d0, dlimit);                               \
+         c = STRING_CHAR (d0, dtemp - d0);                              \
        }                                                                \
      else                                                               \
        (c = ((p) == (str2) ? (end1) : (p))[-1]);                        \
@@ -235,6 +236,7 @@ enum syntaxcode { Swhitespace = 0, Sword = 1 };
 # define SINGLE_BYTE_CHAR_P(c) (1)
 # define SAME_CHARSET_P(c1, c2) (1)
 # define MULTIBYTE_FORM_LENGTH(p, s) (1)
+# define PREV_CHAR_BOUNDARY(p, limit) ((p)--)
 # define STRING_CHAR(p, s) (*(p))
 # define RE_STRING_CHAR STRING_CHAR
 # define CHAR_STRING(c, s) (*(s) = (c), 1)
@@ -4064,6 +4066,10 @@ re_search (bufp, string, size, startpos, range, regs)
 }
 WEAK_ALIAS (__re_search, re_search)
 
+/* Head address of virtual concatenation of string.  */
+#define HEAD_ADDR_VSTRING(P)            \
+  (((P) >= size1 ? string2 : string1))
+
 /* End address of virtual concatenation of string.  */
 #define STOP_ADDR_VSTRING(P)                            \
   (((P) >= size1 ? string2 + size2 : string1 + size1))
@@ -4299,26 +4305,17 @@ re_search_2 (bufp, str1, size1, str2, size2, startpos, range, regs, stop)
           /* Update STARTPOS to the previous character boundary.  */
           if (multibyte)
             {
-              re_char *p = POS_ADDR_VSTRING (startpos);
-              int len = 0;
+              re_char *p = POS_ADDR_VSTRING (startpos) + 1;
+              re_char *p0 = p;
+              re_char *phead = HEAD_ADDR_VSTRING (startpos);
 
               /* Find the head of multibyte form.  */
-              while (!CHAR_HEAD_P (*p))
-                p--, len++;
-
-              /* Adjust it. */
-#if 0                           /* XXX */
-              if (MULTIBYTE_FORM_LENGTH (p, len + 1) != (len + 1))
-                ;
-              else
-#endif
-                {
-                  range += len;
-                  if (range > 0)
-                    break;
+              PREV_CHAR_BOUNDARY (p, phead);
+              range += p0 - 1 - p;
+              if (range > 0)
+                break;
 
-                  startpos -= len;
-                }
+              startpos -= p0 - 1 - p;
             }
         }
     }