After an earlier code cleanup, `dns_rdatalist_tordataset()` always
succeeds, so the `RETERR` error handling macro below the function
call was removed. After that change the `dynbuf` variable can never
be `NULL` in the error handling code path under the `failure` label.
*** CID 355779: Null pointer dereferences (REVERSE_INULL)
/lib/dns/tkey.c: 997 in buildquery()
991 dns_message_puttempname(msg, &aname);
992 }
993 if (question != NULL) {
994 dns_rdataset_disassociate(question);
995 dns_message_puttemprdataset(msg, &question);
996 }
>>> CID 355779: Null pointer dereferences (REVERSE_INULL)
>>> Null-checking "dynbuf" suggests that it may be null, but it has already been dereferenced on all paths leading to the check.
997 if (dynbuf != NULL) {
998 isc_buffer_free(&dynbuf);
999 }
1000 return (result);
1001 }
1002
Refactor the `buildquery()` function to simplify its error handling.