[RFC PATCH 0/5] format-patch: automate cover letter range-diff

[Eric Sunshine <sunshine@sunshineco.com>]

Dscho recently implemented a 'tbdiff' replacement as a Git builtin named
git-branch-diff[1] which computes differences between two versions of a
patch series. Such a diff can be a useful aid for reviewers when
inserted into a cover letter. However, doing so requires manual
generation (invoking git-branch-diff) and copy/pasting the result into
the cover letter.

This series fully automates the process by adding a --range-diff option
to git-format-patch. It is RFC for a couple reasons:

* The final name for the 'tbdiff' replacement has not yet been nailed
  down. The name git-branch-diff is moribund[2]; Dscho favors merging
  the functionality into git-branch as a new --diff option[3]; others
  prefer a standalone command named git-range-diff or
  git-series-diff[4] or similar.

* I have some ideas for future enhancements and want to be careful not
  to lock in a UI which doesn't mesh well with them (though I think the
  current UI turned out reasonably well). First, I foresee a
  complementary --interdiff option for inserting an interdiff-style diff
  for cases when that style is easier to read or simply more
  appropriate. Second, although the current patch series only supports
  --range-diff for the cover letter, some people insert interdiff- or
  tbdiff-style diffs (indented) into the commentary section of
  standalone patches. Although this often makes for a noisy mess, it is
  periodically useful.

This series is built atop js/branch-diff in 'pu'.

[1]: https://public-inbox.org/git/cover.1525448066.git.johannes.schindelin@gmx.de/
[2]: https://public-inbox.org/git/nycvar.QRO.7.76.6.1805061401260.77@tvgsbejvaqbjf.bet/
[3]: https://public-inbox.org/git/nycvar.QRO.7.76.6.1805062155120.77@tvgsbejvaqbjf.bet/
[4]: https://public-inbox.org/git/xmqqin7gzbkb.fsf@gitster-ct.c.googlers.com/

Eric Sunshine (5):
  format-patch: allow additional generated content in
    make_cover_letter()
  format-patch: add --range-diff option to embed diff in cover letter
  format-patch: extend --range-diff to accept revision range
  format-patch: teach --range-diff to respect -v/--reroll-count
  format-patch: add --creation-weight tweak for --range-diff

 Documentation/git-format-patch.txt |  18 +++++
 builtin/log.c                      | 119 ++++++++++++++++++++++++-----
 t/t7910-branch-diff.sh             |  16 ++++
 3 files changed, 132 insertions(+), 21 deletions(-)

-- 
2.17.1.1235.ge295dfb56e