fix case where iob_send sends all from io batch, but then new data is

added and iob_send is called again

io/iob_send.c

@@ -107,16 +107,17 @@ eagain:
     else
       return total?total:sent;
     if (sent==b->bytesleft) {
-      b->bytesleft=0;
 #ifdef TCP_CORK
       if (b->bufs && b->files) {
 	static int zero=0;
 	setsockopt(s,IPPROTO_TCP,TCP_CORK,&zero,sizeof(zero));
       }
 #endif
+      iob_reset(b);
       break;
     } else if (sent>0) {
       int64 rest=sent;
+
       b->bytesleft-=rest;
       for (i=0; e+i<last; ++i) {
 	if (e[i].n<=rest) {