* and the cmsg blocks cannot be modified in-place. */
int i;
if (vlen > IOV_MAX) vlen = IOV_MAX; /* This matches the kernel. */
+ if (!vlen) return 0;
for (i=0; i<vlen; i++) {
/* As an unfortunate inconsistency, the sendmmsg API uses
* unsigned int for the resulting msg_len, despite sendmsg