Fix p_secstodate overflow handling (bug 22463)

[Florian Weimer]

On 11/22/2017 02:06 PM, Joseph Myers wrote:
> On Wed, 22 Nov 2017, Florian Weimer wrote:
> 
>> I think we can change the function to always return NULL (or abort the process
>> with an error message) and turn it into into a compat symbol.  I very much
>> doubt that there are any users at all because the function does not implement
> 
> Well, there are two calls in ns_print.c, so you can't eliminate the
> function without doing something with those calls.

Oh, right, but it has got these gems:

	/* KJD - need to complete this */
	/* XXX need to dump key, print otherdata length & other data */

So maybe we should just fix the generic/default case to use unknown RR 
type syntax and just dump those records in that format.  I'll send 
patches for that once my current round of docs/syscall wrapper work is 
done (too many patches in flight right now).

I don't think DNSSEC as a protocol (or TKEY, which is not part of 
DNSSEC) will survive contact with the year 2038 without changes, so 
doing any proactive Y2038 work here isn't worthwhile IMHO.

Thanks,
Florian