Success and failure tests. This massively increases test coverage for
parsing DNS records, although it doesn’t get it to 100%.
It should now be useful enough to do more fuzzing on, without
immediately getting trivial failures from the fuzzer.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Otherwise the code isn’t forwards-compatible, and may be DOSed by
servers returning unknown records, if `G_DEBUG=fatal-warnings` is
enabled for some reason.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Split out from https://gitlab.gnome.org/GNOME/glib/-/merge_requests/2134
by Philip Withnall so it can be used in advance of HTTPS DNS record
support landing.
Reworked to no longer use test fixtures, as it’s simple enough to build
the response header in each test.
The tests are built on Unix only, as they test the parsing code in
`g_resolver_records_from_res_query()`, which is Unix-specific. The
Windows DNS APIs provide much more structured results which don’t need
parsing.
