From c6de36b9480f6b9c34a3a3bb5ff224eed3de0301 Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Thu, 19 Dec 2013 20:39:26 -0600
Subject: [PATCH] shears.sh: introduce 'bud' and 'finish' commands

The most common operations during splitting a bunch of commits into
neatly-packaged topic branches are:

1) 'finish': name a branch & mark it for merging at the end, and

2) 'bud': start a new branch from the 'onto' commit

Since multiple branches most often want to branch off from a common base
commit, the 'finish' command implies a 'bud' after marking the HEAD for
later merging.

For example, when given an edit script as this:

	pick abcdef Adds an initial README.md file
	pick 012345 Adds a FAQ section to the README
	pick 987654 Fix an off-by-one bug

you might want to put the first two commits into the 'readme' branch
while the third commit wants to live in the 'fixes' branch. This can be
accomplished by inserting two 'finish' lines:

	pick abcdef Adds an initial README.md file
	pick 012345 Adds a FAQ section to the README
	finish readme

	pick 987654 Fix an off-by-one bug
	finish fixes

Since 'finish' implies a 'bud', this will result in a rewritten
history like this:

	* 3141592 Merge 'fixes' into HEAD
	|\
	| * cafebabe Fix an off-by-one bug
	* |  badf00d Merge 'readme' into HEAD
	|\ \
	| * | c0eddad Adds a FAQ section to the README
	| * | d1bad00 Adds an initial README.md file
	|/ /
	o-' fa7d00d Start the merging-rebase

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 share/msysGit/shears.sh | 28 +++++++++++++++++++++++++---
 1 file changed, 25 insertions(+), 3 deletions(-)

diff --git a/share/msysGit/shears.sh b/share/msysGit/shears.sh
index 5c34cfe7..e3f67add 100755
--- a/share/msysGit/shears.sh
+++ b/share/msysGit/shears.sh
@@ -38,7 +38,7 @@ EOF
 }
 
 # Extra commands for use in the rebase script
-extra_commands="edit mark rewind merge start_merging_rebase cleanup"
+extra_commands="edit bud finish mark rewind merge start_merging_rebase cleanup"
 
 edit () {
 	GIT_EDITOR="$1" &&
@@ -71,6 +71,19 @@ rewind () {
 	git reset --hard refs/rewritten/"$1"
 }
 
+bud () {
+	shorthead="$(git rev-parse --short --verify HEAD)" &&
+	git for-each-ref refs/rewritten/ |
+	grep "^$shorthead" ||
+	die "Refusing to leave unmarked revision $shorthead behind"
+	git reset --hard refs/rewritten/onto
+}
+
+finish () {
+	mark "$@" &&
+	bud
+}
+
 merge () {
 	# parse command-line arguments
 	parents=
@@ -129,6 +142,13 @@ cleanup () {
 	do
 		git update-ref -d refs/rewritten/$rewritten
 	done &&
+	for rewritten in $(git for-each-ref refs/rewritten/ |
+		sed 's/^[^ ]* commit.refs\/rewritten\///')
+	do
+		test onto = "$rewritten" ||
+		merge $rewritten
+		git update-ref -d refs/rewritten/$rewritten
+	done &&
 	git config --unset alias..r
 }
 
@@ -274,8 +294,7 @@ EOF
 			# if there is no line, branch from the 'onto' commit
 			if test -z "$line"
 			then
-				subtodo="$(printf '\nexec %s\n%s' \
-					'git reset --hard refs/rewritten/onto' \
+				subtodo="$(printf '\nbud\n%s' \
 					"$subtodo")"
 				break
 			fi
@@ -382,6 +401,9 @@ $command $shortsha1 $oneline")"
 
 this="$(cd "$(dirname "$0")" && pwd)/$(basename "$0")"
 setup () {
+	test -z "$(git for-each-ref refs/rewritten/)" ||
+	die "There are still rewritten revisions"
+
 	alias="$(git config --get alias..r)"
 	test -z "$alias" ||
 	test "a$alias" = "a!sh \"$this\"" ||
-- 
2.11.4.GIT