From 250fab4a8458a697b92b90baa914e9324f587247 Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Sun, 25 Jan 2009 20:58:08 +0100
Subject: [PATCH] rebase -i -p: Add the "merge" command

The syntax is

	"merge parents <parent commits> original <original merge>"

and the action is to merge the given parents, and mark the result as
the rewritten version of the original merge commit.

As "git merge -m <msg>" insists on appending its own message, we
call "commit --amend -m <msg>" after the merge.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 git-rebase--interactive.sh | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 37d87f4e9b..c3ea09c653 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -286,6 +286,34 @@ pick_one () {
 	fi
 }
 
+merge_one () {
+	cmd="merge $*"
+	test "$1" = parents && shift
+	parents=
+	while test "original" != "$1"
+	do
+		parents="$parents $(parse_commit $1)"
+		shift
+	done
+
+	test "original" != "$1" &&
+		die "Could not determine original merge commit from $cmd"
+
+	sha1=$2; shift; shift
+
+	# the command was "merge parents ...", so "parents" was recorded
+# TODO: detect non-fast-forwards properly
+	ORIGINAL_HEAD=$(git rev-parse HEAD) &&
+	git merge $parents &&
+	if test $ORIGINAL_HEAD = "$(git rev-parse HEAD^)"
+	then
+		git commit --amend -m "$*" &&
+		echo "$sha1" > "$REWRITTEN"/original &&
+		add_rewritten
+	fi ||
+	die_with_patch $sha1 "Could not redo merge $sha1 with parents $parents"
+}
+
 pick_one_preserving_merges () {
 	fast_forward=t
 	case "$1" in
@@ -554,6 +582,13 @@ do_next () {
 		output git reset --hard $(parse_commit $sha1) ||
 			die "Could not reset to $sha1"
 		;;
+	merge|m)
+		comment_for_reflog merge
+		mark_action_done
+		# this already dies with patch on error
+		output merge_one $sha1 $rest || # $sha1 is not the real sha1...
+			exit
+		;;
 	*)
 		warn "Unknown command: $command $sha1 $rest"
 		if git rev-parse --verify -q "$sha1" >/dev/null
@@ -946,6 +981,8 @@ first and then run 'git rebase --continue' again."
 #  s, squash = use commit, but meld into previous commit
 #  f, fixup = like "squash", but discard this commit's log message
 #  g, goto = reset the current state to the given commit
+#  m, merge parents <parents> original <original merge commit>
+#          = redo the given merge commit
 #
 # If you remove a line here THAT COMMIT WILL BE LOST.
 # However, if you remove everything, the rebase will be aborted.
-- 
2.11.4.GIT