[PATCH v2 0/2] diff-merges: introduce '-d' option

From: Sergey Organov <sorganov@gmail.com>
Date: Sep 20, 2023, 15:02 UTC
Message-ID: <20230920150244.171772-1-sorganov@gmail.com>
In-Reply-To: <20230909125446.142715-1-sorganov@gmail.com>

This new convenience option requests full diff with respect to first parent, so that

  git log -d

will output diff with respect to first parent for every commit, universally, no matter how many parents the commit turns out to have.

It's implemented as pure synonym for

  --diff-merges=first-parent --patch

The first commit in the series tweaks diff-merges documentation a bit, and is valuable by itself. It's put here as '-d' implementation commit depends on it in its documentation part.

Note: the need for this new convenience option mostly emerged from
denial by the community of patches that modify '-m' behavior to imply
'-p' as the rest of similar options (such as --cc) do.

Updates in v2:

  * Reordered documentation for diff-merges formats in accordance with
    Junio recommendation.

  * Removed clarification of surprising -m behavior due to controversy
    with Junio on how exactly it should look like.

Sergey Organov (2):
  diff-merges: improve --diff-merges documentation
  diff-merges: introduce '-d' option

 Documentation/diff-options.txt | 102 ++++++++++++++++++---------------
 Documentation/git-log.txt      |   4 +-
 diff-merges.c                  |   3 +
 t/t4013-diff-various.sh        |   8 +++
 4 files changed, 70 insertions(+), 47 deletions(-)

Interdiff against v1:

diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index d773dafcb10a..19bb78ff6652 100644
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@ -47,9 +47,6 @@ ifdef::git-log[]
 	Show diffs for merge commits in the default format. This is
 	similar to '--diff-merges=on' (which see) except `-m` will
 	produce no output unless `-p` is given as well.
-+
-Note: This option not implying `-p` is legacy feature that is
-preserved for the sake of backward compatibility.
 
 -d::
 	Produce diff with respect to first parent.
@@ -96,16 +93,6 @@ separate::
 	Show full diff with respect to each of parents.
 	Separate log entry and diff is generated for each parent.
 +
-remerge, r::
-	Remerge two-parent merge commits to create a temporary tree
-	object--potentially containing files with conflict markers
-	and such.  A diff is then shown between that temporary tree
-	and the actual merge commit.
-+
-The output emitted when this option is used is subject to change, and
-so is its interaction with other options (unless explicitly
-documented).
-+
 combined, c::
 	Show differences from each of the parents to the merge
 	result simultaneously instead of showing pairwise diff between
@@ -117,6 +104,16 @@ dense-combined, cc::
 	by omitting uninteresting hunks whose contents in the parents
 	have only two variants and the merge result picks one of them
 	without modification.
++
+remerge, r::
+	Remerge two-parent merge commits to create a temporary tree
+	object--potentially containing files with conflict markers
+	and such.  A diff is then shown between that temporary tree
+	and the actual merge commit.
++
+The output emitted when this option is used is subject to change, and
+so is its interaction with other options (unless explicitly
+documented).
 --
 
 --combined-all-paths::

-- 
2.25.1