[PATCH 0/8] parsing trailers with shortlog

[Jeff King <peff@peff.net>]

Somebody mentioned at the inclusion summit that it would be nice for
mentoring/pairing relationships if we could more easily give credit to
multiple authors of a commit. When people ask about adding multiple
"author" headers, we usually recommend that they use a "co-authored-by"
trailer. But you can't convince shortlog to count it for anything. :)

So this series adds support for counting trailers to shortlog. You can
do a number of fun things with it, like:

    # credit reviewers
    git shortlog -ns --group=trailer:reviewed-by

    # credit authors and co-authors equally
    git shortlog -ns --group=author \
                     --group=trailer:co-authored-by

    # see who helps whom
    git shortlog --format="...helped %an on %as" \
                 --group=trailer:helped-by

If some of this looks familiar, it's because I sent the early patches
years ago. But I won't even bother linking to it; I cleaned up quite a
few rough edges since then, so it's not really worth looking at.

  [1/8]: shortlog: change "author" variables to "ident"
  [2/8]: shortlog: refactor committer/author grouping
  [3/8]: trailer: add interface for iterating over commit trailers
  [4/8]: shortlog: match commit trailers with --group
  [5/8]: shortlog: de-duplicate trailer values
  [6/8]: shortlog: rename parse_stdin_ident()
  [7/8]: shortlog: parse trailer idents
  [8/8]: shortlog: allow multiple groups to be specified

 Documentation/git-shortlog.txt |  29 +++++
 builtin/log.c                  |   1 +
 builtin/shortlog.c             | 218 +++++++++++++++++++++++++++++----
 shortlog.h                     |   8 +-
 t/t4201-shortlog.sh            | 141 +++++++++++++++++++++
 trailer.c                      |  36 ++++++
 trailer.h                      |  44 ++++++-
 7 files changed, 447 insertions(+), 30 deletions(-)

-Peff