Merge branch 'ds/checkout-upper'

[git.git] / strbuf.c

diff --git a/strbuf.c b/strbuf.c
index 536b43204e228a8b7ec8fc3fb44c555157253f8c..b9b194b3200e950cfdb3c696d92ece0657e9d344 100644 (file)
--- a/strbuf.c
+++ b/strbuf.c
@@ -106,17 +106,25 @@ void strbuf_add(struct strbuf *sb, const void *data, size_t len)
        strbuf_setlen(sb, sb->len + len);
 }
 
+void strbuf_adddup(struct strbuf *sb, size_t pos, size_t len)
+{
+       strbuf_grow(sb, len);
+       memcpy(sb->buf + sb->len, sb->buf + pos, len);
+       strbuf_setlen(sb, sb->len + len);
+}
+
 void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
 {
        int len;
        va_list ap;
 
+       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);
-       if (len < 0) {
-               len = 0;
-       }
+       if (len < 0)
+               die("your vsnprintf is broken");
        if (len > strbuf_avail(sb)) {
                strbuf_grow(sb, len);
                va_start(ap, fmt);