bug report: "too many SRV records" becomes "no SRV records"

[Tom Yu]

"Richard E. Silverman" <res at qoxp.net> writes:

> In 1.8.1, there is the following code in src/lib/krb5/os/dnsglue.c:
>
>    krb5int_dns_init(struct krb5int_dns_state **dsp,
>                     char *host, int nclass, int ntype)
>    {
>    ...
>      nextincr = 2048;
>      maxincr = INT_MAX;
>    ...
>
> One day, due to an error, the number of KDC SRV records for one of our
> realms doubled from 27 to 54... and KDC lookups via DNS prompty broke.  I
> bumped up the nextincr value above, and it started working again.
> Probably not the right fix, but just letting you know that there's a bug
> here.

What platform/OS is this on?  A "too-large" response should result in
res_nsearch() returning the actual size.  If it's returning -1
instead, I can see it causing trouble.  Are you willing to run stuff
under a debugger to see what res_nsearch() actually returns there?