Bug#343140: resolver uses search list before other addresses

[Michael Stone <mstone@debian.org>]

> Ok, let's clarify some things here. resolv.conf(5) describes the 
> behaviour of a _single_ resolver query. If you look at 
> resolv/nss_dns/dns-host.c in the glibc source, you'll see that 
> gethostbyname(3) is implemented as _two_ distinct resolver invocations.  
> Since it is nowhere specified how many resolver invocations 
> gethostbyname(3) should cause, the glibc behaviour is correct and will 
> result in the second list of DNS queries you specified.

ISTM that's an issue the user user shouldn't have to care about. 
gethostbyname(3) could be implemented as _four_ distinct resolver 
invocations:

if (inputname doesn't end in ".") {
 resolve(inputname., AAAA)
   return if found
 resolve(inputname., A)
   return if found
}
resolve(inputname, AAAA)
 return if found
resolve(inputname, A)
 return if found

Which would make the results match the requested behavior without a 
major rewrite. "The code does something that makes sense if you look at 
the code" isn't, in itself, a very good reason not to do something 
different.

Mike Stone