rebase: add --quit to cleanup rebase, leave everything else untouched

There are occasions when you decide to abort an in-progress rebase and
move on to do something else but you forget to do "git rebase --abort"
first. Or the rebase has been in progress for so long you forgot about
it. By the time you realize that (e.g. by starting another rebase)
it's already too late to retrace your steps. The solution is normally

    rm -r .git/<some rebase dir>

and continue with your life. But there could be two different
directories for <some rebase dir> (and it obviously requires some
knowledge of how rebase works), and the ".git" part could be much
longer if you are not at top-dir, or in a linked worktree. And
"rm -r" is very dangerous to do in .git, a mistake in there could
destroy object database or other important data.

Provide "git rebase --quit" for this use case, mimicking a precedent
that is "git cherry-pick --quit".

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/git-rebase.sh b/git-rebase.sh
index cf60c4390..c62b17863 100755
--- a/git-rebase.sh
+++ b/git-rebase.sh
@@ -43,6 +43,7 @@ continue!          continue
 abort!             abort and check out the original branch
 skip!              skip current patch and continue
 edit-todo!         edit the todo list during an interactive rebase
+quit!              abort but keep HEAD where it is
 "
 . git-sh-setup
 . git-sh-i18n
@@ -239,7 +240,7 @@ do
 	--verify)
 		ok_to_skip_pre_rebase=
 		;;
-	--continue|--skip|--abort|--edit-todo)
+	--continue|--skip|--abort|--quit|--edit-todo)
 		test $total_argc -eq 2 || usage
 		action=${1##--}
 		;;
@@ -402,6 +403,9 @@ abort)
 	finish_rebase
 	exit
 	;;
+quit)
+	exec rm -rf "$state_dir"
+	;;
 edit-todo)
 	run_specific_rebase
 	;;