From 9681d44ca486596cd97b2e2b2511ed8adeb6f7cd Mon Sep 17 00:00:00 2001
From: Werner Almesberger <werner@almesberger.net>
Date: Sun, 20 May 2012 20:57:18 -0300
Subject: [PATCH] b2/subst.c: use vstring for modified regexp

---
 b2/subst.c | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/b2/subst.c b/b2/subst.c
index 1b8ae36..fea65ef 100644
--- a/b2/subst.c
+++ b/b2/subst.c
@@ -19,6 +19,7 @@
 #include <assert.h>
 
 #include "util.h"
+#include "vstring.h"
 #include "lang.h"
 #include "subst.h"
 
@@ -37,21 +38,28 @@ static struct subst *alloc_subst(enum subst_type type)
 }
 
 
+static char *prepare_re(const char *re)
+{
+	char *res = NULL;
+	int res_len = 0;
+
+	append_char(&res, &res_len, '^');
+	append(&res, &res_len, re);
+	append_char(&res, &res_len, '$');
+	return res;
+}
+
+
 struct subst *subst_match(const char *src, const char *re)
 {
 	char error[1000];
 	struct subst *sub;
 	char *tmp;
-	int err, len;
+	int err;
 
 	sub = alloc_subst(st_match);
 	sub->u.match.src = src;
-	len = strlen(re);
-	tmp = alloc_size(len+3);
-	tmp[0] = '^';
-	memcpy(tmp+1, re, len);
-	tmp[len+1] = '$';
-	tmp[len+2] = 0;
+	tmp = prepare_re(re);
 	err = regcomp(&sub->u.match.re, tmp, REG_EXTENDED);
 	free(tmp);
 	if (err) {