diff -rup a/resolv/res_query.c b/resolv/res_query.c --- a/resolv/res_query.c 2012-02-16 22:51:17.451796009 -0700 +++ b/resolv/res_query.c 2012-02-16 22:54:42.522623598 -0700 @@ -122,6 +122,7 @@ __libc_res_nquery(res_state statp, int *resplen2) { HEADER *hp = (HEADER *) answer; + HEADER *hp2; int n, use_malloc = 0; u_int oflags = statp->_flags; @@ -239,26 +240,25 @@ __libc_res_nquery(res_state statp, /* __libc_res_nsend might have reallocated the buffer. */ hp = (HEADER *) *answerp; - /* We simplify the following tests by assigning HP to HP2. It - is easy to verify that this is the same as ignoring all - tests of HP2. */ - HEADER *hp2 = answerp2 ? (HEADER *) *answerp2 : hp; - - if (n < (int) sizeof (HEADER) && answerp2 != NULL - && *resplen2 > (int) sizeof (HEADER)) + /* We simplify the following tests by assigning HP to HP2 or + vice versa. It is easy to verify that this is the same as + ignoring all tests of HP or HP2. */ + if (answerp2 == NULL || *resplen2 < (int) sizeof (HEADER)) { - /* Special case of partial answer. */ - assert (n == 0 || hp != hp2); - hp = hp2; + hp2 = hp; } - else if (answerp2 != NULL && *resplen2 < (int) sizeof (HEADER) - && n > (int) sizeof (HEADER)) + else { - /* Special case of partial answer. */ - assert (hp != hp2); - hp2 = hp; + hp2 = (HEADER *) *answerp2; + if (n < (int) sizeof (HEADER)) + { + hp = hp2; + } } + /* Make sure both hp and hp2 are defined */ + assert((hp != NULL) && (hp2 != NULL)); + if ((hp->rcode != NOERROR || ntohs(hp->ancount) == 0) && (hp2->rcode != NOERROR || ntohs(hp2->ancount) == 0)) { #ifdef DEBUG