diff --git a/Makefile b/Makefile
index 6d433f8..5b0855c 100644
--- a/Makefile
+++ b/Makefile
@@ -1106,7 +1106,6 @@
 BUILTIN_OBJS += builtin/range-diff.o
 BUILTIN_OBJS += builtin/read-tree.o
 BUILTIN_OBJS += builtin/rebase.o
-BUILTIN_OBJS += builtin/rebase--interactive.o
 BUILTIN_OBJS += builtin/receive-pack.o
 BUILTIN_OBJS += builtin/reflog.o
 BUILTIN_OBJS += builtin/remote.o
diff --git a/builtin/rebase--interactive.c b/builtin/rebase--interactive.c
deleted file mode 100644
index 4535523..0000000
--- a/builtin/rebase--interactive.c
+++ /dev/null
@@ -1,377 +0,0 @@
-#define USE_THE_INDEX_COMPATIBILITY_MACROS
-#include "builtin.h"
-#include "cache.h"
-#include "config.h"
-#include "parse-options.h"
-#include "sequencer.h"
-#include "rebase-interactive.h"
-#include "argv-array.h"
-#include "refs.h"
-#include "rerere.h"
-#include "run-command.h"
-
-static GIT_PATH_FUNC(path_state_dir, "rebase-merge/")
-static GIT_PATH_FUNC(path_squash_onto, "rebase-merge/squash-onto")
-static GIT_PATH_FUNC(path_interactive, "rebase-merge/interactive")
-
-static int add_exec_commands(struct string_list *commands)
-{
-	const char *todo_file = rebase_path_todo();
-	struct todo_list todo_list = TODO_LIST_INIT;
-	int res;
-
-	if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
-		return error_errno(_("could not read '%s'."), todo_file);
-
-	if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
-					&todo_list)) {
-		todo_list_release(&todo_list);
-		return error(_("unusable todo list: '%s'"), todo_file);
-	}
-
-	todo_list_add_exec_commands(&todo_list, commands);
-	res = todo_list_write_to_file(the_repository, &todo_list,
-				      todo_file, NULL, NULL, -1, 0);
-	todo_list_release(&todo_list);
-
-	if (res)
-		return error_errno(_("could not write '%s'."), todo_file);
-	return 0;
-}
-
-static int rearrange_squash_in_todo_file(void)
-{
-	const char *todo_file = rebase_path_todo();
-	struct todo_list todo_list = TODO_LIST_INIT;
-	int res = 0;
-
-	if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
-		return error_errno(_("could not read '%s'."), todo_file);
-	if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
-					&todo_list)) {
-		todo_list_release(&todo_list);
-		return error(_("unusable todo list: '%s'"), todo_file);
-	}
-
-	res = todo_list_rearrange_squash(&todo_list);
-	if (!res)
-		res = todo_list_write_to_file(the_repository, &todo_list,
-					      todo_file, NULL, NULL, -1, 0);
-
-	todo_list_release(&todo_list);
-
-	if (res)
-		return error_errno(_("could not write '%s'."), todo_file);
-	return 0;
-}
-
-static int transform_todo_file(unsigned flags)
-{
-	const char *todo_file = rebase_path_todo();
-	struct todo_list todo_list = TODO_LIST_INIT;
-	int res;
-
-	if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
-		return error_errno(_("could not read '%s'."), todo_file);
-
-	if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
-					&todo_list)) {
-		todo_list_release(&todo_list);
-		return error(_("unusable todo list: '%s'"), todo_file);
-	}
-
-	res = todo_list_write_to_file(the_repository, &todo_list, todo_file,
-				      NULL, NULL, -1, flags);
-	todo_list_release(&todo_list);
-
-	if (res)
-		return error_errno(_("could not write '%s'."), todo_file);
-	return 0;
-}
-
-static int edit_todo_file(unsigned flags)
-{
-	const char *todo_file = rebase_path_todo();
-	struct todo_list todo_list = TODO_LIST_INIT,
-		new_todo = TODO_LIST_INIT;
-	int res = 0;
-
-	if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
-		return error_errno(_("could not read '%s'."), todo_file);
-
-	strbuf_stripspace(&todo_list.buf, 1);
-	res = edit_todo_list(the_repository, &todo_list, &new_todo, NULL, NULL, flags);
-	if (!res && todo_list_write_to_file(the_repository, &new_todo, todo_file,
-					    NULL, NULL, -1, flags & ~(TODO_LIST_SHORTEN_IDS)))
-		res = error_errno(_("could not write '%s'"), todo_file);
-
-	todo_list_release(&todo_list);
-	todo_list_release(&new_todo);
-
-	return res;
-}
-
-static int get_revision_ranges(const char *upstream, const char *onto,
-			       const char **head_hash,
-			       char **revisions, char **shortrevisions)
-{
-	const char *base_rev = upstream ? upstream : onto, *shorthead;
-	struct object_id orig_head;
-
-	if (get_oid("HEAD", &orig_head))
-		return error(_("no HEAD?"));
-
-	*head_hash = find_unique_abbrev(&orig_head, GIT_MAX_HEXSZ);
-	*revisions = xstrfmt("%s...%s", base_rev, *head_hash);
-
-	shorthead = find_unique_abbrev(&orig_head, DEFAULT_ABBREV);
-
-	if (upstream) {
-		const char *shortrev;
-		struct object_id rev_oid;
-
-		get_oid(base_rev, &rev_oid);
-		shortrev = find_unique_abbrev(&rev_oid, DEFAULT_ABBREV);
-
-		*shortrevisions = xstrfmt("%s..%s", shortrev, shorthead);
-	} else
-		*shortrevisions = xstrdup(shorthead);
-
-	return 0;
-}
-
-static int init_basic_state(struct replay_opts *opts, const char *head_name,
-			    const char *onto, const char *orig_head)
-{
-	FILE *interactive;
-
-	if (!is_directory(path_state_dir()) && mkdir_in_gitdir(path_state_dir()))
-		return error_errno(_("could not create temporary %s"), path_state_dir());
-
-	delete_reflog("REBASE_HEAD");
-
-	interactive = fopen(path_interactive(), "w");
-	if (!interactive)
-		return error_errno(_("could not mark as interactive"));
-	fclose(interactive);
-
-	return write_basic_state(opts, head_name, onto, orig_head);
-}
-
-static int do_interactive_rebase(struct replay_opts *opts, unsigned flags,
-				 const char *switch_to, const char *upstream,
-				 const char *onto, const char *onto_name,
-				 const char *squash_onto, const char *head_name,
-				 const char *restrict_revision, char *raw_strategies,
-				 struct string_list *commands, unsigned autosquash)
-{
-	int ret;
-	const char *head_hash = NULL;
-	char *revisions = NULL, *shortrevisions = NULL;
-	struct argv_array make_script_args = ARGV_ARRAY_INIT;
-	struct todo_list todo_list = TODO_LIST_INIT;
-
-	if (prepare_branch_to_be_rebased(opts, switch_to))
-		return -1;
-
-	if (get_revision_ranges(upstream, onto, &head_hash,
-				&revisions, &shortrevisions))
-		return -1;
-
-	if (raw_strategies)
-		parse_strategy_opts(opts, raw_strategies);
-
-	if (init_basic_state(opts, head_name, onto, head_hash)) {
-		free(revisions);
-		free(shortrevisions);
-
-		return -1;
-	}
-
-	if (!upstream && squash_onto)
-		write_file(path_squash_onto(), "%s\n", squash_onto);
-
-	argv_array_pushl(&make_script_args, "", revisions, NULL);
-	if (restrict_revision)
-		argv_array_push(&make_script_args, restrict_revision);
-
-	ret = sequencer_make_script(the_repository, &todo_list.buf,
-				    make_script_args.argc, make_script_args.argv,
-				    flags);
-
-	if (ret)
-		error(_("could not generate todo list"));
-	else {
-		discard_cache();
-		if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
-						&todo_list))
-			BUG("unusable todo list");
-
-		ret = complete_action(the_repository, opts, flags, shortrevisions, onto_name,
-				      onto, head_hash, commands, autosquash, &todo_list);
-	}
-
-	free(revisions);
-	free(shortrevisions);
-	todo_list_release(&todo_list);
-	argv_array_clear(&make_script_args);
-
-	return ret;
-}
-
-static const char * const builtin_rebase_interactive_usage[] = {
-	N_("git rebase--interactive [<options>]"),
-	NULL
-};
-
-int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
-{
-	struct replay_opts opts = REPLAY_OPTS_INIT;
-	unsigned flags = 0, keep_empty = 0, rebase_merges = 0, autosquash = 0;
-	int abbreviate_commands = 0, rebase_cousins = -1, ret = 0;
-	const char *onto = NULL, *onto_name = NULL, *restrict_revision = NULL,
-		*squash_onto = NULL, *upstream = NULL, *head_name = NULL,
-		*switch_to = NULL, *cmd = NULL;
-	struct string_list commands = STRING_LIST_INIT_DUP;
-	char *raw_strategies = NULL;
-	enum {
-		NONE = 0, CONTINUE, SKIP, EDIT_TODO, SHOW_CURRENT_PATCH,
-		SHORTEN_OIDS, EXPAND_OIDS, CHECK_TODO_LIST, REARRANGE_SQUASH, ADD_EXEC
-	} command = 0;
-	struct option options[] = {
-		OPT_BOOL(0, "ff", &opts.allow_ff, N_("allow fast-forward")),
-		OPT_BOOL(0, "keep-empty", &keep_empty, N_("keep empty commits")),
-		OPT_BOOL(0, "allow-empty-message", &opts.allow_empty_message,
-			 N_("allow commits with empty messages")),
-		OPT_BOOL(0, "rebase-merges", &rebase_merges, N_("rebase merge commits")),
-		OPT_BOOL(0, "rebase-cousins", &rebase_cousins,
-			 N_("keep original branch points of cousins")),
-		OPT_BOOL(0, "autosquash", &autosquash,
-			 N_("move commits that begin with squash!/fixup!")),
-		OPT_BOOL(0, "signoff", &opts.signoff, N_("sign commits")),
-		OPT__VERBOSE(&opts.verbose, N_("be verbose")),
-		OPT_CMDMODE(0, "continue", &command, N_("continue rebase"),
-			    CONTINUE),
-		OPT_CMDMODE(0, "skip", &command, N_("skip commit"), SKIP),
-		OPT_CMDMODE(0, "edit-todo", &command, N_("edit the todo list"),
-			    EDIT_TODO),
-		OPT_CMDMODE(0, "show-current-patch", &command, N_("show the current patch"),
-			    SHOW_CURRENT_PATCH),
-		OPT_CMDMODE(0, "shorten-ids", &command,
-			N_("shorten commit ids in the todo list"), SHORTEN_OIDS),
-		OPT_CMDMODE(0, "expand-ids", &command,
-			N_("expand commit ids in the todo list"), EXPAND_OIDS),
-		OPT_CMDMODE(0, "check-todo-list", &command,
-			N_("check the todo list"), CHECK_TODO_LIST),
-		OPT_CMDMODE(0, "rearrange-squash", &command,
-			N_("rearrange fixup/squash lines"), REARRANGE_SQUASH),
-		OPT_CMDMODE(0, "add-exec-commands", &command,
-			N_("insert exec commands in todo list"), ADD_EXEC),
-		OPT_STRING(0, "onto", &onto, N_("onto"), N_("onto")),
-		OPT_STRING(0, "restrict-revision", &restrict_revision,
-			   N_("restrict-revision"), N_("restrict revision")),
-		OPT_STRING(0, "squash-onto", &squash_onto, N_("squash-onto"),
-			   N_("squash onto")),
-		OPT_STRING(0, "upstream", &upstream, N_("upstream"),
-			   N_("the upstream commit")),
-		OPT_STRING(0, "head-name", &head_name, N_("head-name"), N_("head name")),
-		{ OPTION_STRING, 'S', "gpg-sign", &opts.gpg_sign, N_("key-id"),
-			N_("GPG-sign commits"),
-			PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
-		OPT_STRING(0, "strategy", &opts.strategy, N_("strategy"),
-			   N_("rebase strategy")),
-		OPT_STRING(0, "strategy-opts", &raw_strategies, N_("strategy-opts"),
-			   N_("strategy options")),
-		OPT_STRING(0, "switch-to", &switch_to, N_("switch-to"),
-			   N_("the branch or commit to checkout")),
-		OPT_STRING(0, "onto-name", &onto_name, N_("onto-name"), N_("onto name")),
-		OPT_STRING(0, "cmd", &cmd, N_("cmd"), N_("the command to run")),
-		OPT_RERERE_AUTOUPDATE(&opts.allow_rerere_auto),
-		OPT_BOOL(0, "reschedule-failed-exec", &opts.reschedule_failed_exec,
-			 N_("automatically re-schedule any `exec` that fails")),
-		OPT_END()
-	};
-
-	sequencer_init_config(&opts);
-	git_config_get_bool("rebase.abbreviatecommands", &abbreviate_commands);
-
-	opts.action = REPLAY_INTERACTIVE_REBASE;
-	opts.allow_ff = 1;
-	opts.allow_empty = 1;
-
-	if (argc == 1)
-		usage_with_options(builtin_rebase_interactive_usage, options);
-
-	argc = parse_options(argc, argv, NULL, options,
-			builtin_rebase_interactive_usage, PARSE_OPT_KEEP_ARGV0);
-
-	opts.gpg_sign = xstrdup_or_null(opts.gpg_sign);
-
-	flags |= keep_empty ? TODO_LIST_KEEP_EMPTY : 0;
-	flags |= abbreviate_commands ? TODO_LIST_ABBREVIATE_CMDS : 0;
-	flags |= rebase_merges ? TODO_LIST_REBASE_MERGES : 0;
-	flags |= rebase_cousins > 0 ? TODO_LIST_REBASE_COUSINS : 0;
-	flags |= command == SHORTEN_OIDS ? TODO_LIST_SHORTEN_IDS : 0;
-
-	if (rebase_cousins >= 0 && !rebase_merges)
-		warning(_("--[no-]rebase-cousins has no effect without "
-			  "--rebase-merges"));
-
-	if (cmd && *cmd) {
-		string_list_split(&commands, cmd, '\n', -1);
-
-		/* rebase.c adds a new line to cmd after every command,
-		 * so here the last command is always empty */
-		string_list_remove_empty_items(&commands, 0);
-	}
-
-	switch (command) {
-	case NONE:
-		if (!onto && !upstream)
-			die(_("a base commit must be provided with --upstream or --onto"));
-
-		ret = do_interactive_rebase(&opts, flags, switch_to, upstream, onto,
-					    onto_name, squash_onto, head_name, restrict_revision,
-					    raw_strategies, &commands, autosquash);
-		break;
-	case SKIP: {
-		struct string_list merge_rr = STRING_LIST_INIT_DUP;
-
-		rerere_clear(the_repository, &merge_rr);
-		/* fallthrough */
-	case CONTINUE:
-		ret = sequencer_continue(the_repository, &opts);
-		break;
-	}
-	case EDIT_TODO:
-		ret = edit_todo_file(flags);
-		break;
-	case SHOW_CURRENT_PATCH: {
-		struct child_process cmd = CHILD_PROCESS_INIT;
-
-		cmd.git_cmd = 1;
-		argv_array_pushl(&cmd.args, "show", "REBASE_HEAD", "--", NULL);
-		ret = run_command(&cmd);
-
-		break;
-	}
-	case SHORTEN_OIDS:
-	case EXPAND_OIDS:
-		ret = transform_todo_file(flags);
-		break;
-	case CHECK_TODO_LIST:
-		ret = check_todo_list_from_file(the_repository);
-		break;
-	case REARRANGE_SQUASH:
-		ret = rearrange_squash_in_todo_file();
-		break;
-	case ADD_EXEC:
-		ret = add_exec_commands(&commands);
-		break;
-	default:
-		BUG("invalid command '%d'", command);
-	}
-
-	string_list_clear(&commands, 0);
-	return !!ret;
-}
diff --git a/builtin/rebase.c b/builtin/rebase.c
index 966b953..ba3a574 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -25,6 +25,8 @@
 #include "commit-reach.h"
 #include "rerere.h"
 #include "branch.h"
+#include "sequencer.h"
+#include "rebase-interactive.h"
 
 static char const * const builtin_rebase_usage[] = {
 	N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
@@ -35,6 +37,8 @@
 	NULL
 };
 
+static GIT_PATH_FUNC(path_squash_onto, "rebase-merge/squash-onto")
+static GIT_PATH_FUNC(path_interactive, "rebase-merge/interactive")
 static GIT_PATH_FUNC(apply_dir, "rebase-apply")
 static GIT_PATH_FUNC(merge_dir, "rebase-merge")
 
@@ -86,6 +90,437 @@
 	int use_legacy_rebase;
 };
 
+#define REBASE_OPTIONS_INIT {			  	\
+		.type = REBASE_UNSPECIFIED,	  	\
+		.flags = REBASE_NO_QUIET, 		\
+		.git_am_opts = ARGV_ARRAY_INIT,		\
+		.git_format_patch_opt = STRBUF_INIT	\
+	}
+
+static struct replay_opts get_replay_opts(const struct rebase_options *opts)
+{
+	struct replay_opts replay = REPLAY_OPTS_INIT;
+
+	replay.action = REPLAY_INTERACTIVE_REBASE;
+	sequencer_init_config(&replay);
+
+	replay.signoff = opts->signoff;
+	replay.allow_ff = !(opts->flags & REBASE_FORCE);
+	if (opts->allow_rerere_autoupdate)
+		replay.allow_rerere_auto = opts->allow_rerere_autoupdate;
+	replay.allow_empty = 1;
+	replay.allow_empty_message = opts->allow_empty_message;
+	replay.verbose = opts->flags & REBASE_VERBOSE;
+	replay.reschedule_failed_exec = opts->reschedule_failed_exec;
+	replay.gpg_sign = xstrdup_or_null(opts->gpg_sign_opt);
+	replay.strategy = opts->strategy;
+	if (opts->strategy_opts)
+		parse_strategy_opts(&replay, opts->strategy_opts);
+
+	return replay;
+}
+
+enum action {
+	ACTION_NONE = 0,
+	ACTION_CONTINUE,
+	ACTION_SKIP,
+	ACTION_ABORT,
+	ACTION_QUIT,
+	ACTION_EDIT_TODO,
+	ACTION_SHOW_CURRENT_PATCH,
+	ACTION_SHORTEN_OIDS,
+	ACTION_EXPAND_OIDS,
+	ACTION_CHECK_TODO_LIST,
+	ACTION_REARRANGE_SQUASH,
+	ACTION_ADD_EXEC
+};
+
+static const char *action_names[] = { "undefined",
+				      "continue",
+				      "skip",
+				      "abort",
+				      "quit",
+				      "edit_todo",
+				      "show_current_patch" };
+
+static int add_exec_commands(struct string_list *commands)
+{
+	const char *todo_file = rebase_path_todo();
+	struct todo_list todo_list = TODO_LIST_INIT;
+	int res;
+
+	if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
+		return error_errno(_("could not read '%s'."), todo_file);
+
+	if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
+					&todo_list)) {
+		todo_list_release(&todo_list);
+		return error(_("unusable todo list: '%s'"), todo_file);
+	}
+
+	todo_list_add_exec_commands(&todo_list, commands);
+	res = todo_list_write_to_file(the_repository, &todo_list,
+				      todo_file, NULL, NULL, -1, 0);
+	todo_list_release(&todo_list);
+
+	if (res)
+		return error_errno(_("could not write '%s'."), todo_file);
+	return 0;
+}
+
+static int rearrange_squash_in_todo_file(void)
+{
+	const char *todo_file = rebase_path_todo();
+	struct todo_list todo_list = TODO_LIST_INIT;
+	int res = 0;
+
+	if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
+		return error_errno(_("could not read '%s'."), todo_file);
+	if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
+					&todo_list)) {
+		todo_list_release(&todo_list);
+		return error(_("unusable todo list: '%s'"), todo_file);
+	}
+
+	res = todo_list_rearrange_squash(&todo_list);
+	if (!res)
+		res = todo_list_write_to_file(the_repository, &todo_list,
+					      todo_file, NULL, NULL, -1, 0);
+
+	todo_list_release(&todo_list);
+
+	if (res)
+		return error_errno(_("could not write '%s'."), todo_file);
+	return 0;
+}
+
+static int transform_todo_file(unsigned flags)
+{
+	const char *todo_file = rebase_path_todo();
+	struct todo_list todo_list = TODO_LIST_INIT;
+	int res;
+
+	if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
+		return error_errno(_("could not read '%s'."), todo_file);
+
+	if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
+					&todo_list)) {
+		todo_list_release(&todo_list);
+		return error(_("unusable todo list: '%s'"), todo_file);
+	}
+
+	res = todo_list_write_to_file(the_repository, &todo_list, todo_file,
+				      NULL, NULL, -1, flags);
+	todo_list_release(&todo_list);
+
+	if (res)
+		return error_errno(_("could not write '%s'."), todo_file);
+	return 0;
+}
+
+static int edit_todo_file(unsigned flags)
+{
+	const char *todo_file = rebase_path_todo();
+	struct todo_list todo_list = TODO_LIST_INIT,
+		new_todo = TODO_LIST_INIT;
+	int res = 0;
+
+	if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
+		return error_errno(_("could not read '%s'."), todo_file);
+
+	strbuf_stripspace(&todo_list.buf, 1);
+	res = edit_todo_list(the_repository, &todo_list, &new_todo, NULL, NULL, flags);
+	if (!res && todo_list_write_to_file(the_repository, &new_todo, todo_file,
+					    NULL, NULL, -1, flags & ~(TODO_LIST_SHORTEN_IDS)))
+		res = error_errno(_("could not write '%s'"), todo_file);
+
+	todo_list_release(&todo_list);
+	todo_list_release(&new_todo);
+
+	return res;
+}
+
+static int get_revision_ranges(struct commit *upstream, struct commit *onto,
+			       const char **head_hash,
+			       char **revisions, char **shortrevisions)
+{
+	struct commit *base_rev = upstream ? upstream : onto;
+	const char *shorthead;
+	struct object_id orig_head;
+
+	if (get_oid("HEAD", &orig_head))
+		return error(_("no HEAD?"));
+
+	*head_hash = find_unique_abbrev(&orig_head, GIT_MAX_HEXSZ);
+	*revisions = xstrfmt("%s...%s", oid_to_hex(&base_rev->object.oid),
+						   *head_hash);
+
+	shorthead = find_unique_abbrev(&orig_head, DEFAULT_ABBREV);
+
+	if (upstream) {
+		const char *shortrev;
+
+		shortrev = find_unique_abbrev(&base_rev->object.oid,
+					      DEFAULT_ABBREV);
+
+		*shortrevisions = xstrfmt("%s..%s", shortrev, shorthead);
+	} else
+		*shortrevisions = xstrdup(shorthead);
+
+	return 0;
+}
+
+static int init_basic_state(struct replay_opts *opts, const char *head_name,
+			    struct commit *onto, const char *orig_head)
+{
+	FILE *interactive;
+
+	if (!is_directory(merge_dir()) && mkdir_in_gitdir(merge_dir()))
+		return error_errno(_("could not create temporary %s"), merge_dir());
+
+	delete_reflog("REBASE_HEAD");
+
+	interactive = fopen(path_interactive(), "w");
+	if (!interactive)
+		return error_errno(_("could not mark as interactive"));
+	fclose(interactive);
+
+	return write_basic_state(opts, head_name, onto, orig_head);
+}
+
+static void split_exec_commands(const char *cmd, struct string_list *commands)
+{
+	if (cmd && *cmd) {
+		string_list_split(commands, cmd, '\n', -1);
+
+		/* rebase.c adds a new line to cmd after every command,
+		 * so here the last command is always empty */
+		string_list_remove_empty_items(commands, 0);
+	}
+}
+
+static int do_interactive_rebase(struct rebase_options *opts, unsigned flags)
+{
+	int ret;
+	const char *head_hash = NULL;
+	char *revisions = NULL, *shortrevisions = NULL;
+	struct argv_array make_script_args = ARGV_ARRAY_INIT;
+	struct todo_list todo_list = TODO_LIST_INIT;
+	struct replay_opts replay = get_replay_opts(opts);
+	struct string_list commands = STRING_LIST_INIT_DUP;
+
+	if (prepare_branch_to_be_rebased(the_repository, &replay,
+					 opts->switch_to))
+		return -1;
+
+	if (get_revision_ranges(opts->upstream, opts->onto, &head_hash,
+				&revisions, &shortrevisions))
+		return -1;
+
+	if (init_basic_state(&replay,
+			     opts->head_name ? opts->head_name : "detached HEAD",
+			     opts->onto, head_hash)) {
+		free(revisions);
+		free(shortrevisions);
+
+		return -1;
+	}
+
+	if (!opts->upstream && opts->squash_onto)
+		write_file(path_squash_onto(), "%s\n",
+			   oid_to_hex(opts->squash_onto));
+
+	argv_array_pushl(&make_script_args, "", revisions, NULL);
+	if (opts->restrict_revision)
+		argv_array_push(&make_script_args,
+				oid_to_hex(&opts->restrict_revision->object.oid));
+
+	ret = sequencer_make_script(the_repository, &todo_list.buf,
+				    make_script_args.argc, make_script_args.argv,
+				    flags);
+
+	if (ret)
+		error(_("could not generate todo list"));
+	else {
+		discard_cache();
+		if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
+						&todo_list))
+			BUG("unusable todo list");
+
+		split_exec_commands(opts->cmd, &commands);
+		ret = complete_action(the_repository, &replay, flags,
+			shortrevisions, opts->onto_name, opts->onto, head_hash,
+			&commands, opts->autosquash, &todo_list);
+	}
+
+	string_list_clear(&commands, 0);
+	free(revisions);
+	free(shortrevisions);
+	todo_list_release(&todo_list);
+	argv_array_clear(&make_script_args);
+
+	return ret;
+}
+
+static int run_rebase_interactive(struct rebase_options *opts,
+				  enum action command)
+{
+	unsigned flags = 0;
+	int abbreviate_commands = 0, ret = 0;
+
+	git_config_get_bool("rebase.abbreviatecommands", &abbreviate_commands);
+
+	flags |= opts->keep_empty ? TODO_LIST_KEEP_EMPTY : 0;
+	flags |= abbreviate_commands ? TODO_LIST_ABBREVIATE_CMDS : 0;
+	flags |= opts->rebase_merges ? TODO_LIST_REBASE_MERGES : 0;
+	flags |= opts->rebase_cousins > 0 ? TODO_LIST_REBASE_COUSINS : 0;
+	flags |= command == ACTION_SHORTEN_OIDS ? TODO_LIST_SHORTEN_IDS : 0;
+
+	switch (command) {
+	case ACTION_NONE: {
+		if (!opts->onto && !opts->upstream)
+			die(_("a base commit must be provided with --upstream or --onto"));
+
+		ret = do_interactive_rebase(opts, flags);
+		break;
+	}
+	case ACTION_SKIP: {
+		struct string_list merge_rr = STRING_LIST_INIT_DUP;
+
+		rerere_clear(the_repository, &merge_rr);
+	}
+		/* fallthrough */
+	case ACTION_CONTINUE: {
+		struct replay_opts replay_opts = get_replay_opts(opts);
+
+		ret = sequencer_continue(the_repository, &replay_opts);
+		break;
+	}
+	case ACTION_EDIT_TODO:
+		ret = edit_todo_file(flags);
+		break;
+	case ACTION_SHOW_CURRENT_PATCH: {
+		struct child_process cmd = CHILD_PROCESS_INIT;
+
+		cmd.git_cmd = 1;
+		argv_array_pushl(&cmd.args, "show", "REBASE_HEAD", "--", NULL);
+		ret = run_command(&cmd);
+
+		break;
+	}
+	case ACTION_SHORTEN_OIDS:
+	case ACTION_EXPAND_OIDS:
+		ret = transform_todo_file(flags);
+		break;
+	case ACTION_CHECK_TODO_LIST:
+		ret = check_todo_list_from_file(the_repository);
+		break;
+	case ACTION_REARRANGE_SQUASH:
+		ret = rearrange_squash_in_todo_file();
+		break;
+	case ACTION_ADD_EXEC: {
+		struct string_list commands = STRING_LIST_INIT_DUP;
+
+		split_exec_commands(opts->cmd, &commands);
+		ret = add_exec_commands(&commands);
+		string_list_clear(&commands, 0);
+		break;
+	}
+	default:
+		BUG("invalid command '%d'", command);
+	}
+
+	return ret;
+}
+
+static const char * const builtin_rebase_interactive_usage[] = {
+	N_("git rebase--interactive [<options>]"),
+	NULL
+};
+
+int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
+{
+	struct rebase_options opts = REBASE_OPTIONS_INIT;
+	struct object_id squash_onto = null_oid;
+	enum action command = ACTION_NONE;
+	struct option options[] = {
+		OPT_NEGBIT(0, "ff", &opts.flags, N_("allow fast-forward"),
+			   REBASE_FORCE),
+		OPT_BOOL(0, "keep-empty", &opts.keep_empty, N_("keep empty commits")),
+		OPT_BOOL(0, "allow-empty-message", &opts.allow_empty_message,
+			 N_("allow commits with empty messages")),
+		OPT_BOOL(0, "rebase-merges", &opts.rebase_merges, N_("rebase merge commits")),
+		OPT_BOOL(0, "rebase-cousins", &opts.rebase_cousins,
+			 N_("keep original branch points of cousins")),
+		OPT_BOOL(0, "autosquash", &opts.autosquash,
+			 N_("move commits that begin with squash!/fixup!")),
+		OPT_BOOL(0, "signoff", &opts.signoff, N_("sign commits")),
+		OPT_BIT('v', "verbose", &opts.flags,
+			N_("display a diffstat of what changed upstream"),
+			REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
+		OPT_CMDMODE(0, "continue", &command, N_("continue rebase"),
+			    ACTION_CONTINUE),
+		OPT_CMDMODE(0, "skip", &command, N_("skip commit"), ACTION_SKIP),
+		OPT_CMDMODE(0, "edit-todo", &command, N_("edit the todo list"),
+			    ACTION_EDIT_TODO),
+		OPT_CMDMODE(0, "show-current-patch", &command, N_("show the current patch"),
+			    ACTION_SHOW_CURRENT_PATCH),
+		OPT_CMDMODE(0, "shorten-ids", &command,
+			N_("shorten commit ids in the todo list"), ACTION_SHORTEN_OIDS),
+		OPT_CMDMODE(0, "expand-ids", &command,
+			N_("expand commit ids in the todo list"), ACTION_EXPAND_OIDS),
+		OPT_CMDMODE(0, "check-todo-list", &command,
+			N_("check the todo list"), ACTION_CHECK_TODO_LIST),
+		OPT_CMDMODE(0, "rearrange-squash", &command,
+			N_("rearrange fixup/squash lines"), ACTION_REARRANGE_SQUASH),
+		OPT_CMDMODE(0, "add-exec-commands", &command,
+			N_("insert exec commands in todo list"), ACTION_ADD_EXEC),
+		{ OPTION_CALLBACK, 0, "onto", &opts.onto, N_("onto"), N_("onto"),
+		  PARSE_OPT_NONEG, parse_opt_commit, 0 },
+		{ OPTION_CALLBACK, 0, "restrict-revision", &opts.restrict_revision,
+		  N_("restrict-revision"), N_("restrict revision"),
+		  PARSE_OPT_NONEG, parse_opt_commit, 0 },
+		{ OPTION_CALLBACK, 0, "squash-onto", &squash_onto, N_("squash-onto"),
+		  N_("squash onto"), PARSE_OPT_NONEG, parse_opt_object_id, 0 },
+		{ OPTION_CALLBACK, 0, "upstream", &opts.upstream, N_("upstream"),
+		  N_("the upstream commit"), PARSE_OPT_NONEG, parse_opt_commit,
+		  0 },
+		OPT_STRING(0, "head-name", &opts.head_name, N_("head-name"), N_("head name")),
+		{ OPTION_STRING, 'S', "gpg-sign", &opts.gpg_sign_opt, N_("key-id"),
+			N_("GPG-sign commits"),
+			PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
+		OPT_STRING(0, "strategy", &opts.strategy, N_("strategy"),
+			   N_("rebase strategy")),
+		OPT_STRING(0, "strategy-opts", &opts.strategy_opts, N_("strategy-opts"),
+			   N_("strategy options")),
+		OPT_STRING(0, "switch-to", &opts.switch_to, N_("switch-to"),
+			   N_("the branch or commit to checkout")),
+		OPT_STRING(0, "onto-name", &opts.onto_name, N_("onto-name"), N_("onto name")),
+		OPT_STRING(0, "cmd", &opts.cmd, N_("cmd"), N_("the command to run")),
+		OPT_RERERE_AUTOUPDATE(&opts.allow_rerere_autoupdate),
+		OPT_BOOL(0, "reschedule-failed-exec", &opts.reschedule_failed_exec,
+			 N_("automatically re-schedule any `exec` that fails")),
+		OPT_END()
+	};
+
+	opts.rebase_cousins = -1;
+
+	if (argc == 1)
+		usage_with_options(builtin_rebase_interactive_usage, options);
+
+	argc = parse_options(argc, argv, NULL, options,
+			builtin_rebase_interactive_usage, PARSE_OPT_KEEP_ARGV0);
+
+	if (!is_null_oid(&squash_onto))
+		opts.squash_onto = &squash_onto;
+
+	if (opts.rebase_cousins >= 0 && !opts.rebase_merges)
+		warning(_("--[no-]rebase-cousins has no effect without "
+			  "--rebase-merges"));
+
+	return !!run_rebase_interactive(&opts, command);
+}
+
 static int is_interactive(struct rebase_options *opts)
 {
 	return opts->type == REBASE_INTERACTIVE ||
@@ -184,14 +619,13 @@
 			    &buf))
 			return -1;
 		if (!strcmp(buf.buf, "--rerere-autoupdate"))
-			opts->allow_rerere_autoupdate = 1;
+			opts->allow_rerere_autoupdate = RERERE_AUTOUPDATE;
 		else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
-			opts->allow_rerere_autoupdate = 0;
+			opts->allow_rerere_autoupdate = RERERE_NOAUTOUPDATE;
 		else
 			warning(_("ignoring invalid allow_rerere_autoupdate: "
 				  "'%s'"), buf.buf);
-	} else
-		opts->allow_rerere_autoupdate = -1;
+	}
 
 	if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 		strbuf_reset(&buf);
@@ -223,7 +657,7 @@
 	return 0;
 }
 
-static int write_basic_state(struct rebase_options *opts)
+static int rebase_write_basic_state(struct rebase_options *opts)
 {
 	write_file(state_dir_path("head-name", opts), "%s",
 		   opts->head_name ? opts->head_name : "detached HEAD");
@@ -241,10 +675,11 @@
 	if (opts->strategy_opts)
 		write_file(state_dir_path("strategy_opts", opts), "%s",
 			   opts->strategy_opts);
-	if (opts->allow_rerere_autoupdate >= 0)
+	if (opts->allow_rerere_autoupdate > 0)
 		write_file(state_dir_path("allow_rerere_autoupdate", opts),
 			   "-%s-rerere-autoupdate",
-			   opts->allow_rerere_autoupdate ? "" : "-no");
+			   opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
+				"" : "-no");
 	if (opts->gpg_sign_opt)
 		write_file(state_dir_path("gpg_sign_opt", opts), "%s",
 			   opts->gpg_sign_opt);
@@ -608,9 +1043,9 @@
 	argv_array_push(&am.args, "--rebasing");
 	argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 	argv_array_push(&am.args, "--patch-format=mboxrd");
-	if (opts->allow_rerere_autoupdate > 0)
+	if (opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE)
 		argv_array_push(&am.args, "--rerere-autoupdate");
-	else if (opts->allow_rerere_autoupdate == 0)
+	else if (opts->allow_rerere_autoupdate == RERERE_NOAUTOUPDATE)
 		argv_array_push(&am.args, "--no-rerere-autoupdate");
 	if (opts->gpg_sign_opt)
 		argv_array_push(&am.args, opts->gpg_sign_opt);
@@ -623,12 +1058,12 @@
 	}
 
 	if (is_directory(opts->state_dir))
-		write_basic_state(opts);
+		rebase_write_basic_state(opts);
 
 	return status;
 }
 
-static int run_specific_rebase(struct rebase_options *opts)
+static int run_specific_rebase(struct rebase_options *opts, enum action action)
 {
 	const char *argv[] = { NULL, NULL };
 	struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
@@ -637,77 +1072,19 @@
 
 	if (opts->type == REBASE_INTERACTIVE) {
 		/* Run builtin interactive rebase */
-		struct child_process child = CHILD_PROCESS_INIT;
-
-		argv_array_pushf(&child.env_array, "GIT_CHERRY_PICK_HELP=%s",
-				 resolvemsg);
+		setenv("GIT_CHERRY_PICK_HELP", resolvemsg, 1);
 		if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
-			argv_array_push(&child.env_array,
-					"GIT_SEQUENCE_EDITOR=:");
+			setenv("GIT_SEQUENCE_EDITOR", ":", 1);
 			opts->autosquash = 0;
 		}
+		if (opts->gpg_sign_opt) {
+			/* remove the leading "-S" */
+			char *tmp = xstrdup(opts->gpg_sign_opt + 2);
+			free(opts->gpg_sign_opt);
+			opts->gpg_sign_opt = tmp;
+		}
 
-		child.git_cmd = 1;
-		argv_array_push(&child.args, "rebase--interactive");
-
-		if (opts->action)
-			argv_array_pushf(&child.args, "--%s", opts->action);
-		if (opts->keep_empty)
-			argv_array_push(&child.args, "--keep-empty");
-		if (opts->rebase_merges)
-			argv_array_push(&child.args, "--rebase-merges");
-		if (opts->rebase_cousins)
-			argv_array_push(&child.args, "--rebase-cousins");
-		if (opts->autosquash)
-			argv_array_push(&child.args, "--autosquash");
-		if (opts->flags & REBASE_VERBOSE)
-			argv_array_push(&child.args, "--verbose");
-		if (opts->flags & REBASE_FORCE)
-			argv_array_push(&child.args, "--no-ff");
-		if (opts->restrict_revision)
-			argv_array_pushf(&child.args,
-					 "--restrict-revision=^%s",
-					 oid_to_hex(&opts->restrict_revision->object.oid));
-		if (opts->upstream)
-			argv_array_pushf(&child.args, "--upstream=%s",
-					 oid_to_hex(&opts->upstream->object.oid));
-		if (opts->onto)
-			argv_array_pushf(&child.args, "--onto=%s",
-					 oid_to_hex(&opts->onto->object.oid));
-		if (opts->squash_onto)
-			argv_array_pushf(&child.args, "--squash-onto=%s",
-					 oid_to_hex(opts->squash_onto));
-		if (opts->onto_name)
-			argv_array_pushf(&child.args, "--onto-name=%s",
-					 opts->onto_name);
-		argv_array_pushf(&child.args, "--head-name=%s",
-				 opts->head_name ?
-				 opts->head_name : "detached HEAD");
-		if (opts->strategy)
-			argv_array_pushf(&child.args, "--strategy=%s",
-					 opts->strategy);
-		if (opts->strategy_opts)
-			argv_array_pushf(&child.args, "--strategy-opts=%s",
-					 opts->strategy_opts);
-		if (opts->switch_to)
-			argv_array_pushf(&child.args, "--switch-to=%s",
-					 opts->switch_to);
-		if (opts->cmd)
-			argv_array_pushf(&child.args, "--cmd=%s", opts->cmd);
-		if (opts->allow_empty_message)
-			argv_array_push(&child.args, "--allow-empty-message");
-		if (opts->allow_rerere_autoupdate > 0)
-			argv_array_push(&child.args, "--rerere-autoupdate");
-		else if (opts->allow_rerere_autoupdate == 0)
-			argv_array_push(&child.args, "--no-rerere-autoupdate");
-		if (opts->gpg_sign_opt)
-			argv_array_push(&child.args, opts->gpg_sign_opt);
-		if (opts->signoff)
-			argv_array_push(&child.args, "--signoff");
-		if (opts->reschedule_failed_exec)
-			argv_array_push(&child.args, "--reschedule-failed-exec");
-
-		status = run_command(&child);
+		status = run_rebase_interactive(opts, action);
 		goto finished_rebase;
 	}
 
@@ -747,9 +1124,9 @@
 	add_var(&script_snippet, "action", opts->action ? opts->action : "");
 	add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
 	add_var(&script_snippet, "allow_rerere_autoupdate",
-		opts->allow_rerere_autoupdate < 0 ? "" :
 		opts->allow_rerere_autoupdate ?
-		"--rerere-autoupdate" : "--no-rerere-autoupdate");
+			opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
+			"--rerere-autoupdate" : "--no-rerere-autoupdate" : "");
 	add_var(&script_snippet, "keep_empty", opts->keep_empty ? "yes" : "");
 	add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
 	add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
@@ -991,14 +1368,7 @@
 
 int cmd_rebase(int argc, const char **argv, const char *prefix)
 {
-	struct rebase_options options = {
-		.type = REBASE_UNSPECIFIED,
-		.flags = REBASE_NO_QUIET,
-		.git_am_opts = ARGV_ARRAY_INIT,
-		.allow_rerere_autoupdate  = -1,
-		.allow_empty_message = 1,
-		.git_format_patch_opt = STRBUF_INIT,
-	};
+	struct rebase_options options = REBASE_OPTIONS_INIT;
 	const char *branch_name;
 	int ret, flags, total_argc, in_progress = 0;
 	int ok_to_skip_pre_rebase = 0;
@@ -1006,23 +1376,7 @@
 	struct strbuf revisions = STRBUF_INIT;
 	struct strbuf buf = STRBUF_INIT;
 	struct object_id merge_base;
-	enum {
-		NO_ACTION,
-		ACTION_CONTINUE,
-		ACTION_SKIP,
-		ACTION_ABORT,
-		ACTION_QUIT,
-		ACTION_EDIT_TODO,
-		ACTION_SHOW_CURRENT_PATCH,
-	} action = NO_ACTION;
-	static const char *action_names[] = { N_("undefined"),
-					      N_("continue"),
-					      N_("skip"),
-					      N_("abort"),
-					      N_("quit"),
-					      N_("edit_todo"),
-					      N_("show_current_patch"),
-					      NULL };
+	enum action action = ACTION_NONE;
 	const char *gpg_sign = NULL;
 	struct string_list exec = STRING_LIST_INIT_NODUP;
 	const char *rebase_merges = NULL;
@@ -1090,10 +1444,7 @@
 		OPT_SET_INT('p', "preserve-merges", &options.type,
 			    N_("(DEPRECATED) try to recreate merges instead of "
 			       "ignoring them"), REBASE_PRESERVE_MERGES),
-		OPT_BOOL(0, "rerere-autoupdate",
-			 &options.allow_rerere_autoupdate,
-			 N_("allow rerere to update index with resolved "
-			    "conflict")),
+		OPT_RERERE_AUTOUPDATE(&options.allow_rerere_autoupdate),
 		OPT_BOOL('k', "keep-empty", &options.keep_empty,
 			 N_("preserve empty commits during rebase")),
 		OPT_BOOL(0, "autosquash", &options.autosquash,
@@ -1139,6 +1490,7 @@
 	trace_repo_setup(prefix);
 	setup_work_tree();
 
+	options.allow_empty_message = 1;
 	git_config(rebase_config, &options);
 
 	if (options.use_legacy_rebase ||
@@ -1180,7 +1532,7 @@
 			     builtin_rebase_options,
 			     builtin_rebase_usage, 0);
 
-	if (action != NO_ACTION && total_argc != 2) {
+	if (action != ACTION_NONE && total_argc != 2) {
 		usage_with_options(builtin_rebase_usage,
 				   builtin_rebase_options);
 	}
@@ -1193,7 +1545,7 @@
 		warning(_("git rebase --preserve-merges is deprecated. "
 			  "Use --rebase-merges instead."));
 
-	if (action != NO_ACTION && !in_progress)
+	if (action != ACTION_NONE && !in_progress)
 		die(_("No rebase in progress?"));
 	setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
 
@@ -1293,7 +1645,7 @@
 		options.action = "show-current-patch";
 		options.dont_finish_rebase = 1;
 		goto run_rebase;
-	case NO_ACTION:
+	case ACTION_NONE:
 		break;
 	default:
 		BUG("action: %d", action);
@@ -1791,7 +2143,7 @@
 	options.revisions = revisions.buf;
 
 run_rebase:
-	ret = !!run_specific_rebase(&options);
+	ret = !!run_specific_rebase(&options, action);
 
 cleanup:
 	strbuf_release(&revisions);
diff --git a/parse-options-cb.c b/parse-options-cb.c
index 6e2e8d6..4b95d04 100644
--- a/parse-options-cb.c
+++ b/parse-options-cb.c
@@ -96,6 +96,23 @@
 	return 0;
 }
 
+int parse_opt_commit(const struct option *opt, const char *arg, int unset)
+{
+	struct object_id oid;
+	struct commit *commit;
+	struct commit **target = opt->value;
+
+	if (!arg)
+		return -1;
+	if (get_oid(arg, &oid))
+		return error("malformed object name %s", arg);
+	commit = lookup_commit_reference(the_repository, &oid);
+	if (!commit)
+		return error("no such commit %s", arg);
+	*target = commit;
+	return 0;
+}
+
 int parse_opt_object_name(const struct option *opt, const char *arg, int unset)
 {
 	struct object_id oid;
@@ -112,6 +129,23 @@
 	return 0;
 }
 
+int parse_opt_object_id(const struct option *opt, const char *arg, int unset)
+{
+	struct object_id oid;
+	struct object_id *target = opt->value;
+
+	if (unset) {
+		*target = null_oid;
+		return 0;
+	}
+	if (!arg)
+		return -1;
+	if (get_oid(arg, &oid))
+		return error(_("malformed object name '%s'"), arg);
+	*target = oid;
+	return 0;
+}
+
 int parse_opt_tertiary(const struct option *opt, const char *arg, int unset)
 {
 	int *target = opt->value;
diff --git a/parse-options.h b/parse-options.h
index 1dd3523..bd00cf0 100644
--- a/parse-options.h
+++ b/parse-options.h
@@ -277,8 +277,12 @@
 int parse_opt_expiry_date_cb(const struct option *, const char *, int);
 int parse_opt_color_flag_cb(const struct option *, const char *, int);
 int parse_opt_verbosity_cb(const struct option *, const char *, int);
+/* value is struct oid_array* */
 int parse_opt_object_name(const struct option *, const char *, int);
+/* value is struct object_id* */
+int parse_opt_object_id(const struct option *, const char *, int);
 int parse_opt_commits(const struct option *, const char *, int);
+int parse_opt_commit(const struct option *, const char *, int);
 int parse_opt_tertiary(const struct option *, const char *, int);
 int parse_opt_string_list(const struct option *, const char *, int);
 int parse_opt_noop_cb(const struct option *, const char *, int);
diff --git a/sequencer.c b/sequencer.c
index 4407a3f..72a1bc5 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -2494,14 +2494,15 @@
 }
 
 int write_basic_state(struct replay_opts *opts, const char *head_name,
-		      const char *onto, const char *orig_head)
+		      struct commit *onto, const char *orig_head)
 {
 	const char *quiet = getenv("GIT_QUIET");
 
 	if (head_name)
 		write_file(rebase_path_head_name(), "%s\n", head_name);
 	if (onto)
-		write_file(rebase_path_onto(), "%s\n", onto);
+		write_file(rebase_path_onto(), "%s\n",
+			   oid_to_hex(&onto->object.oid));
 	if (orig_head)
 		write_file(rebase_path_orig_head(), "%s\n", orig_head);
 
@@ -3517,10 +3518,11 @@
 	return buf.buf;
 }
 
-static int run_git_checkout(struct replay_opts *opts, const char *commit,
-			    const char *action)
+static int run_git_checkout(struct repository *r, struct replay_opts *opts,
+			    const char *commit, const char *action)
 {
 	struct child_process cmd = CHILD_PROCESS_INIT;
+	int ret;
 
 	cmd.git_cmd = 1;
 
@@ -3529,26 +3531,32 @@
 	argv_array_pushf(&cmd.env_array, GIT_REFLOG_ACTION "=%s", action);
 
 	if (opts->verbose)
-		return run_command(&cmd);
+		ret = run_command(&cmd);
 	else
-		return run_command_silent_on_success(&cmd);
+		ret = run_command_silent_on_success(&cmd);
+
+	if (!ret)
+		discard_index(r->index);
+
+	return ret;
 }
 
-int prepare_branch_to_be_rebased(struct replay_opts *opts, const char *commit)
+int prepare_branch_to_be_rebased(struct repository *r, struct replay_opts *opts,
+				 const char *commit)
 {
 	const char *action;
 
 	if (commit && *commit) {
 		action = reflog_message(opts, "start", "checkout %s", commit);
-		if (run_git_checkout(opts, commit, action))
+		if (run_git_checkout(r, opts, commit, action))
 			return error(_("could not checkout %s"), commit);
 	}
 
 	return 0;
 }
 
-static int checkout_onto(struct replay_opts *opts,
-			 const char *onto_name, const char *onto,
+static int checkout_onto(struct repository *r, struct replay_opts *opts,
+			 const char *onto_name, const struct object_id *onto,
 			 const char *orig_head)
 {
 	struct object_id oid;
@@ -3557,7 +3565,7 @@
 	if (get_oid(orig_head, &oid))
 		return error(_("%s: not a valid OID"), orig_head);
 
-	if (run_git_checkout(opts, onto, action)) {
+	if (run_git_checkout(r, opts, oid_to_hex(onto), action)) {
 		apply_autostash(opts);
 		sequencer_remove_state(opts);
 		return error(_("could not detach HEAD"));
@@ -4833,16 +4841,16 @@
 
 int complete_action(struct repository *r, struct replay_opts *opts, unsigned flags,
 		    const char *shortrevisions, const char *onto_name,
-		    const char *onto, const char *orig_head, struct string_list *commands,
-		    unsigned autosquash, struct todo_list *todo_list)
+		    struct commit *onto, const char *orig_head,
+		    struct string_list *commands, unsigned autosquash,
+		    struct todo_list *todo_list)
 {
 	const char *shortonto, *todo_file = rebase_path_todo();
 	struct todo_list new_todo = TODO_LIST_INIT;
 	struct strbuf *buf = &todo_list->buf;
-	struct object_id oid;
+	struct object_id oid = onto->object.oid;
 	int res;
 
-	get_oid(onto, &oid);
 	shortonto = find_unique_abbrev(&oid, DEFAULT_ABBREV);
 
 	if (buf->len == 0) {
@@ -4885,7 +4893,7 @@
 	if (todo_list_parse_insn_buffer(r, new_todo.buf.buf, &new_todo) ||
 	    todo_list_check(todo_list, &new_todo)) {
 		fprintf(stderr, _(edit_todo_list_advice));
-		checkout_onto(opts, onto_name, onto, orig_head);
+		checkout_onto(r, opts, onto_name, &onto->object.oid, orig_head);
 		todo_list_release(&new_todo);
 
 		return -1;
@@ -4904,7 +4912,7 @@
 
 	todo_list_release(&new_todo);
 
-	if (checkout_onto(opts, onto_name, oid_to_hex(&oid), orig_head))
+	if (checkout_onto(r, opts, onto_name, &oid, orig_head))
 		return -1;
 
 	if (require_clean_work_tree(r, "rebase", "", 1, 1))
diff --git a/sequencer.h b/sequencer.h
index 75e292c..f4a8f4e 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -151,7 +151,7 @@
 int check_todo_list_from_file(struct repository *r);
 int complete_action(struct repository *r, struct replay_opts *opts, unsigned flags,
 		    const char *shortrevisions, const char *onto_name,
-		    const char *onto, const char *orig_head, struct string_list *commands,
+		    struct commit *onto, const char *orig_head, struct string_list *commands,
 		    unsigned autosquash, struct todo_list *todo_list);
 int todo_list_rearrange_squash(struct todo_list *todo_list);
 
@@ -183,7 +183,8 @@
 			 const struct commit *current_head,
 			 const struct object_id *new_head);
 
-int prepare_branch_to_be_rebased(struct replay_opts *opts, const char *commit);
+int prepare_branch_to_be_rebased(struct repository *r, struct replay_opts *opts,
+				 const char *commit);
 
 #define SUMMARY_INITIAL_COMMIT   (1 << 0)
 #define SUMMARY_SHOW_AUTHOR_DATE (1 << 1)
@@ -198,4 +199,4 @@
 
 void parse_strategy_opts(struct replay_opts *opts, char *raw_opts);
 int write_basic_state(struct replay_opts *opts, const char *head_name,
-		      const char *onto, const char *orig_head);
+		      struct commit *onto, const char *orig_head);