ref-filter.h: provide `REF_FILTER_INIT`

Provide a sane initialization value for `struct ref_filter`, which in a
subsequent patch will be used to initialize a new field.

In the meantime, ensure that the `ref_filter` struct used in the
test-helper's `cmd__reach()` is zero-initialized. The lack of
initialization is OK, since `commit_contains()` only looks at the single
`with_commit_tag_algo` field that *is* initialized directly above.

So this does not fix a bug, but rather prevents one from biting us in
the future.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

0 files changed, 0 insertions, 0 deletions