X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=strbuf.c;h=09c43ae59a7d4715c26f13d72ca37bc759d1c76d;hb=53c632faab0be2e8510a678a4b7dfa01dc7f41e1;hp=07e8883ceb297bdde79f06ffa2d0519581ee60b9;hpb=625589b5bebb95a13732c15b7c680c8b1540035b;p=git.git

diff --git a/strbuf.c b/strbuf.c
index 07e8883ce..09c43ae59 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -30,8 +30,10 @@ void strbuf_init(struct strbuf *sb, size_t hint)
 {
 	sb->alloc = sb->len = 0;
 	sb->buf = strbuf_slopbuf;
-	if (hint)
+	if (hint) {
 		strbuf_grow(sb, hint);
+		sb->buf[0] = '\0';
+	}
 }
 
 void strbuf_release(struct strbuf *sb)
@@ -195,24 +197,29 @@ void strbuf_adddup(struct strbuf *sb, size_t pos, size_t len)
 
 void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
 {
-	int len;
 	va_list ap;
+	va_start(ap, fmt);
+	strbuf_vaddf(sb, fmt, ap);
+	va_end(ap);
+}
+
+void strbuf_vaddf(struct strbuf *sb, const char *fmt, va_list ap)
+{
+	int len;
+	va_list cp;
 
 	if (!strbuf_avail(sb))
 		strbuf_grow(sb, 64);
-	va_start(ap, fmt);
-	len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
-	va_end(ap);
+	va_copy(cp, ap);
+	len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, cp);
+	va_end(cp);
 	if (len < 0)
-		die("your vsnprintf is broken");
+		die("BUG: your vsnprintf is broken (returned %d)", len);
 	if (len > strbuf_avail(sb)) {
 		strbuf_grow(sb, len);
-		va_start(ap, fmt);
 		len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
-		va_end(ap);
-		if (len > strbuf_avail(sb)) {
-			die("this should not happen, your snprintf is broken");
-		}
+		if (len > strbuf_avail(sb))
+			die("BUG: your vsnprintf is broken (insatiable)");
 	}
 	strbuf_setlen(sb, sb->len + len);
 }