Bug#182886: libc6: local hostnames containing a dot get forwarded outside when doing host-lookups.
Quoting from resolv.conf(5):
options Allows certain internal resolver variables to be modified. The
options option ...
where option is one of the following:
debug sets RES_DEBUG in _res.options.
ndots:n sets a threshold for the number of dots which must
appear in a name given to res_query() (see
resolver(3)) before an initial absolute query will be
made. The default for n is ``1'', meaning that if
there are any dots in a name, the name will be tried
first as an absolute name before any search list ele-
ments are appended to it.
So it looks like to achieve what you suggest the ndots default
should be adjusted according to the local policy during the installation