gaih_getanswer (const querybuf *answer1, int anslen1, const querybuf *answer2,
		int anslen2, const char *qname,
		struct gaih_addrtuple **pat, char *buffer, size_t buflen,
		int *errnop, int *h_errnop, int32_t *ttlp)
{
  int first = 1;

  enum nss_status status = NSS_STATUS_NOTFOUND;

  /* Combining the NSS status of two distinct queries requires some
     compromise and attention to symmetry (A or AAAA queries can be
     returned in any order).  What follows is a breakdown of how this
     code is expected to work and why. We discuss only SUCCESS,
     TRYAGAIN, NOTFOUND and UNAVAIL, since they are the only returns
     that apply (though RETURN and MERGE exist).  We make a distinction
     between TRYAGAIN (recoverable) and TRYAGAIN' (not-recoverable).
     A recoverable TRYAGAIN is almost always due to buffer size issues
     and returns ERANGE in errno and the caller is expected to retry
     with a larger buffer.

     Lastly, you may be tempted to make significant changes to the
     conditions in this code to bring about symmetry between responses.
     Please don't change anything without due consideration for
     expected application behaviour.  Some of the synthesized responses
     aren't very well thought out and sometimes appear to imply that
     IPv4 responses are always answer 1, and IPv6 responses are always
     answer 2, but that's not true (see the implementation of send_dg
     and send_vc to see response can arrive in any order, particularly
     for UDP). However, we expect it holds roughly enough of the time
     that this code works, but certainly needs to be fixed to make this
     a more robust implementation.

     ----------------------------------------------
     | Answer 1 Status /   | Synthesized | Reason |
     | Answer 2 Status     | Status      |        |
     |--------------------------------------------|
     | SUCCESS/SUCCESS     | SUCCESS     | [1]    |
     | SUCCESS/TRYAGAIN    | TRYAGAIN    | [5]    |
     | SUCCESS/TRYAGAIN'   | SUCCESS     | [1]    |
     | SUCCESS/NOTFOUND    | SUCCESS     | [1]    |
     | SUCCESS/UNAVAIL     | SUCCESS     | [1]    |
     | TRYAGAIN/SUCCESS    | TRYAGAIN    | [2]    |
     | TRYAGAIN/TRYAGAIN   | TRYAGAIN    | [2]    |
     | TRYAGAIN/TRYAGAIN'  | TRYAGAIN    | [2]    |
     | TRYAGAIN/NOTFOUND   | TRYAGAIN    | [2]    |
     | TRYAGAIN/UNAVAIL    | TRYAGAIN    | [2]    |
     | TRYAGAIN'/SUCCESS   | SUCCESS     | [3]    |
     | TRYAGAIN'/TRYAGAIN  | TRYAGAIN    | [3]    |
     | TRYAGAIN'/TRYAGAIN' | TRYAGAIN'   | [3]    |
     | TRYAGAIN'/NOTFOUND  | TRYAGAIN'   | [3]    |
     | TRYAGAIN'/UNAVAIL   | UNAVAIL     | [3]    |
     | NOTFOUND/SUCCESS    | SUCCESS     | [3]    |
     | NOTFOUND/TRYAGAIN   | TRYAGAIN    | [3]    |
     | NOTFOUND/TRYAGAIN'  | TRYAGAIN'   | [3]    |
     | NOTFOUND/NOTFOUND   | NOTFOUND    | [3]    |
     | NOTFOUND/UNAVAIL    | UNAVAIL     | [3]    |
     | UNAVAIL/SUCCESS     | UNAVAIL     | [4]    |
     | UNAVAIL/TRYAGAIN    | UNAVAIL     | [4]    |
     | UNAVAIL/TRYAGAIN'   | UNAVAIL     | [4]    |
     | UNAVAIL/NOTFOUND    | UNAVAIL     | [4]    |
     | UNAVAIL/UNAVAIL     | UNAVAIL     | [4]    |
     ----------------------------------------------

     [1] If the first response is a success we return success.
	 This ignores the state of the second answer and in fact
	 incorrectly sets errno and h_errno to that of the second
	 answer.  However because the response is a success we ignore
	 *errnop and *h_errnop (though that means you touched errno on
	 success).  We are being conservative here and returning the
	 likely IPv4 response in the first answer as a success.

     [2] If the first response is a recoverable TRYAGAIN we return
	 that instead of looking at the second response.  The
	 expectation here is that we have failed to get an IPv4 response
	 and should retry both queries.

     [3] If the first response was not a SUCCESS and the second
	 response is not NOTFOUND (had a SUCCESS, need to TRYAGAIN,
	 or failed entirely e.g. TRYAGAIN' and UNAVAIL) then use the
	 result from the second response, otherwise the first responses
	 status is used.  Again we have some odd side-effects when the
	 second response is NOTFOUND because we overwrite *errnop and
	 *h_errnop that means that a first answer of NOTFOUND might see
	 its *errnop and *h_errnop values altered.  Whether it matters
	 in practice that a first response NOTFOUND has the wrong
	 *errnop and *h_errnop is undecided.

     [4] If the first response is UNAVAIL we return that instead of
	 looking at the second response.  The expectation here is that
	 it will have failed similarly e.g. configuration failure.

     [5] Testing this code is complicated by the fact that truncated
	 second response buffers might be returned as SUCCESS if the
	 first answer is a SUCCESS.  To fix this we add symmetry to
	 TRYAGAIN with the second response.  If the second response
	 is a recoverable error we now return TRYAGIN even if the first
	 response was SUCCESS.  */

  if (anslen1 > 0)
    status = gaih_getanswer_slice(answer1, anslen1, qname,
				  &pat, &buffer, &buflen,
				  errnop, h_errnop, ttlp,
				  &first);

  if ((status == NSS_STATUS_SUCCESS || status == NSS_STATUS_NOTFOUND
       || (status == NSS_STATUS_TRYAGAIN
	   /* We want to look at the second answer in case of an
	      NSS_STATUS_TRYAGAIN only if the error is non-recoverable, i.e.
	      *h_errnop is NO_RECOVERY. If not, and if the failure was due to
	      an insufficient buffer (ERANGE), then we need to drop the results
	      and pass on the NSS_STATUS_TRYAGAIN to the caller so that it can
	      repeat the query with a larger buffer.  */
	   && (*errnop != ERANGE || *h_errnop == NO_RECOVERY)))
      && answer2 != NULL && anslen2 > 0)
    {
      enum nss_status status2 = gaih_getanswer_slice(answer2, anslen2, qname,
						     &pat, &buffer, &buflen,
						     errnop, h_errnop, ttlp,
						     &first);
      /* Use the second response status in some cases.  */
      if (status != NSS_STATUS_SUCCESS && status2 != NSS_STATUS_NOTFOUND)
	status = status2;
      /* Do not return a truncated second response (unless it was
	 unavoidable e.g. unrecoverable TRYAGAIN).  */
      if (status == NSS_STATUS_SUCCESS
	  && (status2 == NSS_STATUS_TRYAGAIN
	      && *errnop == ERANGE && *h_errnop != NO_RECOVERY))
	status = NSS_STATUS_TRYAGAIN;
    }

  return status;
}