const char *fmt, ...) PRINTFFORMAT(4,5);
int adns__vbuf_ensure(vbuf *vb, int want);
-int adns__vbuf_appendstr(vbuf *vb, const char *data);
+int adns__vbuf_appendstr(vbuf *vb, const char *data); /* does not include nul */
int adns__vbuf_append(vbuf *vb, const byte *data, int len);
/* 1=>success, 0=>realloc failed */
void adns__vbuf_appendq(vbuf *vb, const byte *data, int len);