buffers/search: allow displaying results in reverse

Not hooked up to any commands, so not actually usable yet.

Note that oldest_first and newest_first sort orders are not inverses of
each other, because oldest_first uses the oldest message in the thread
for sorting, while newest_first uses the newest one.

This option applies on top of that sorting to display results from the
end to the beginning. This requires reading the whole result list first,
so can be slow for queries with many results.

0 files changed, 0 insertions, 0 deletions