[PATCH/RFC] rebase: new convenient option to edit/reword/delete a single commit

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

Prepare the todo list for you to edit/reword/delete the given commit.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 Allowing multiple actions is a bit too much for my shell skills. I
 don't really need it so I won't push it, but if somebody gives me a
 sketch, I'll try to polish it.

 --squash and --fixup would require two commits, making it a bit
 awkward in option handling. Or is the fixup/squash always HEAD?

 Documentation/git-rebase.txt | 11 +++++++++++
 git-rebase--interactive.sh   | 17 ++++++++++++++---
 git-rebase.sh                | 22 +++++++++++++++++++++-
 3 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index 2a93c64..becb749 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -13,6 +13,7 @@ SYNOPSIS
 'git rebase' [-i | --interactive] [options] [--exec <cmd>] [--onto <newbase>]
 	--root [<branch>]
 'git rebase' --continue | --skip | --abort | --edit-todo
+'git rebase' [--edit | -E | --reword | -R | --delete | -D ] <commit-ish>
 
 DESCRIPTION
 -----------
@@ -356,6 +357,16 @@ unless the `--fork-point` option is specified.
 	user edit that list before rebasing.  This mode can also be used to
 	split commits (see SPLITTING COMMITS below).
 
+-E=<commit>::
+--edit=<commit>::
+-R=<commit>::
+--reword=<commit>::
+-D=<commit>::
+--delete=<commit>::
+	Prepare the todo list to edit or reword or delete the
+	specified commit. Configuration variable `rebase.autostash` is
+	ignored.
+
 -p::
 --preserve-merges::
 	Instead of ignoring merges, try to recreate them.
diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index a1adae8..3ded4c7 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -1040,9 +1040,20 @@ fi
 has_action "$todo" ||
 	die_abort "Nothing to do"
 
-cp "$todo" "$todo".backup
-git_sequence_editor "$todo" ||
-	die_abort "Could not execute editor"
+if test -n "$one_action"
+then
+	commit="`git rev-parse --short $one_commit`"
+	sed "1s/pick $commit /$one_action $commit /" "$todo" > "$todo.new" ||
+		die_abort "failed to update todo list"
+	grep "^$one_action $commit " "$todo.new" >/dev/null ||
+		die_abort "expected to find '$one_action $commit' line but did not"
+	mv "$todo.new" "$todo" ||
+		die_abort "failed to update todo list"
+else
+	cp "$todo" "$todo".backup
+	git_sequence_editor "$todo" ||
+		die_abort "Could not execute editor"
+fi
 
 has_action "$todo" ||
 	die_abort "Nothing to do"
diff --git a/git-rebase.sh b/git-rebase.sh
index 5f6732b..2acffb4 100755
--- a/git-rebase.sh
+++ b/git-rebase.sh
@@ -32,6 +32,9 @@ verify             allow pre-rebase hook to run
 rerere-autoupdate  allow rerere to update index with resolved conflicts
 root!              rebase all reachable commits up to the root(s)
 autosquash         move commits that begin with squash!/fixup! under -i
+E,edit=!           generate todo list to edit this commit
+R,reword=!         generate todo list to reword this commit's message
+D,delete=!         generate todo list to delete this commit
 committer-date-is-author-date! passed to 'git am'
 ignore-date!       passed to 'git am'
 whitespace=!       passed to 'git apply'
@@ -228,6 +231,7 @@ then
 fi
 test -n "$type" && in_progress=t
 
+one_action=
 total_argc=$#
 while test $# != 0
 do
@@ -290,6 +294,7 @@ do
 		;;
 	--autostash)
 		autostash=true
+		explicit_autosquash=t
 		;;
 	--verbose)
 		verbose=t
@@ -335,6 +340,13 @@ do
 	--gpg-sign=*)
 		gpg_sign_opt="-S${1#--gpg-sign=}"
 		;;
+	--edit=*|--reword=*|--delete=*)
+		test -n "$one_action" && die "$(gettext "--edit, --reword or --delete cannot be used multiple times")"
+		interactive_rebase=explicit
+		one_action="${1%=*}"
+		one_action="${one_action#--}"
+		one_commit="${1#--*=}"
+		;;
 	--)
 		shift
 		break
@@ -342,6 +354,7 @@ do
 	esac
 	shift
 done
+test -n "$one_action" && test $# -gt 0 && usage
 test $# -gt 2 && usage
 
 if test -n "$cmd" &&
@@ -438,7 +451,14 @@ else
 	state_dir="$apply_dir"
 fi
 
-if test -z "$rebase_root"
+if test -n "$one_action"
+then
+	upstream_name="$one_commit^"
+	upstream=$(peel_committish "${upstream_name}") ||
+	die "$(eval_gettext "invalid upstream \$upstream_name")"
+	upstream_arg="$upstream_name"
+	test -n "$explicit_autosquash" || autosquash=
+elif test -z "$rebase_root"
 then
 	case "$#" in
 	0)
-- 
1.9.0.40.gaa8c3ea