Now that shortlog supports reading from trailers, it can be useful to
combine counts from multiple trailers, or between trailers and authors.
This can be done manually by post-processing the output from multiple
runs, but it's non-trivial to make sure that each name/commit pair is
counted only once.
This patch teaches shortlog to accept multiple --group options on the
command line, and pull data from all of them. That makes it possible to
run:
git shortlog -ns --group=author --group=trailer:co-authored-by
to get a shortlog that counts authors and co-authors equally.
The implementation is mostly straightforward. The "group" enum becomes a
bitfield, and the trailer key becomes a list. I didn't bother
implementing the multi-group semantics for reading from stdin. It would
be possible to do, but the existing matching code makes it awkward, and
I doubt anybody cares.
The duplicate suppression we used for trailers now covers authors and
committers as well (though in non-trailer single-group mode we can skip
the hash insertion and lookup, since we only see one value per commit).
There is one subtlety: we now care about the case when no group bit is
set (in which case we default to showing the author). The caller in
builtin/log.c needs to be adapted to ask explicitly for authors, rather
than relying on shortlog_init(). It would be possible with some
gymnastics to make this keep working as-is, but it's not worth it for a
single caller.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
63d24fa0b0