add tests for various blame formats

diff --git a/strbuf.c b/strbuf.c
index 07e8883ceb297bdde79f06ffa2d0519581ee60b9..09c43ae59a7d4715c26f13d72ca37bc759d1c76d 100644 (file)
--- 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);
 }