Each reftable addition has an associated update_index. While writing
refs, the update_index is verified to be within the range of the
reftable writer, i.e. `writer.min_update_index <= ref.update_index` and
`writer.max_update_index => ref.update_index`.
The corresponding check for reflogs in `reftable_writer_add_log` is
however missing. Add a similar check, but only check for the upper
limit. This is because reflogs are treated a bit differently than refs.
Each reflog entry in reftable has an associated update_index and we also
allow expiring entries in the middle, which is done by simply writing a
new reflog entry with the same update_index. This means, writing reflog
entries with update_index lesser than the writer's update_index is an
expected scenario.
Add a new unit test to check for the limits and fix some of the existing
tests, which were setting arbitrary values for the update_index by
ensuring they stay within the now checked limits.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>