[PATCH 0/4] builtin/diff: learn --merge-base

The range-notation in `git diff` has been cited as a mistake since diff compares two endpoints, not whole ranges.[0] In fact, the ranges seem to take on the opposite meanings when compared to range notation in `git log`.

In an effort to reduce the use of range notation as much as possible, introduce the `--merge-base` flag, slightly modified from a suggestion by Jonathan Nieder.[1] This flag allows us to replace the first commit given on the command-line with its merge base between the first and second commits. This allows us to gently deprecate the `...` form entirely, although that is left as an exercise to the reader ;)

One additional bonus is that this flag allows the "after" side to be not just constrained to a commit (like with `...` notation). It can now be the working tree or the index as well.

[0]: https://lore.kernel.org/git/xmqqy2v26hu0.fsf@gitster-ct.c.googlers.com/ [1]: https://lore.kernel.org/git/20191223215928.GB38316@google.com/

Denton Liu (4):
  t4068: remove unnecessary >tmp
  git-diff.txt: backtick quote command text
  builtin/diff: parse --no-index using parse_options()
  builtin/diff: learn --merge-base

 Documentation/git-diff.txt | 40 ++++++++++++-----
 builtin/diff.c             | 92 +++++++++++++++++++++++++++++++++-----
 diff-no-index.c            | 15 ++-----
 t/t4068-diff-symmetric.sh  | 89 +++++++++++++++++++++++++++++++++---
 4 files changed, 197 insertions(+), 39 deletions(-)