- int r = __res_msend(1, &msg, &msglen, &answer, &anslen, anslen);
- return r<0 ? r : anslen;
+ int r;
+ if (anslen < 512) {
+ unsigned char buf[512];
+ r = __res_send(msg, msglen, buf, sizeof buf);
+ if (r >= 0) memcpy(answer, buf, r < anslen ? r : anslen);
+ return r;
+ }
+ r = __res_msend(1, &msg, &msglen, &answer, &anslen, anslen);
+ return r<0 || !anslen ? -1 : anslen;