Adding upstream version 1:2.39.2.upstream/1%2.39.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1837 insertions, 0 deletions

diff --git a/builtin/rebase.c b/builtin/rebase.c
new file mode 100644
index 0000000..b22768c
--- /dev/null
+++ b/builtin/rebase.c
@@ -0,0 +1,1837 @@
+/*
+ * "git rebase" builtin command
+ *
+ * Copyright (c) 2018 Pratik Karki
+ */
+
+#define USE_THE_INDEX_VARIABLE
+#include "builtin.h"
+#include "run-command.h"
+#include "exec-cmd.h"
+#include "strvec.h"
+#include "dir.h"
+#include "packfile.h"
+#include "refs.h"
+#include "quote.h"
+#include "config.h"
+#include "cache-tree.h"
+#include "unpack-trees.h"
+#include "lockfile.h"
+#include "parse-options.h"
+#include "commit.h"
+#include "diff.h"
+#include "wt-status.h"
+#include "revision.h"
+#include "commit-reach.h"
+#include "rerere.h"
+#include "branch.h"
+#include "sequencer.h"
+#include "rebase-interactive.h"
+#include "reset.h"
+#include "hook.h"
+
+static char const * const builtin_rebase_usage[] = {
+	N_("git rebase [-i] [options] [--exec <cmd>] "
+		"[--onto <newbase> | --keep-base] [<upstream> [<branch>]]"),
+	N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
+		"--root [<branch>]"),
+	"git rebase --continue | --abort | --skip | --edit-todo",
+	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")
+
+enum rebase_type {
+	REBASE_UNSPECIFIED = -1,
+	REBASE_APPLY,
+	REBASE_MERGE
+};
+
+enum empty_type {
+	EMPTY_UNSPECIFIED = -1,
+	EMPTY_DROP,
+	EMPTY_KEEP,
+	EMPTY_ASK
+};
+
+enum action {
+	ACTION_NONE = 0,
+	ACTION_CONTINUE,
+	ACTION_SKIP,
+	ACTION_ABORT,
+	ACTION_QUIT,
+	ACTION_EDIT_TODO,
+	ACTION_SHOW_CURRENT_PATCH
+};
+
+static const char *action_names[] = {
+	"undefined",
+	"continue",
+	"skip",
+	"abort",
+	"quit",
+	"edit_todo",
+	"show_current_patch"
+};
+
+struct rebase_options {
+	enum rebase_type type;
+	enum empty_type empty;
+	const char *default_backend;
+	const char *state_dir;
+	struct commit *upstream;
+	const char *upstream_name;
+	const char *upstream_arg;
+	char *head_name;
+	struct commit *orig_head;
+	struct commit *onto;
+	const char *onto_name;
+	const char *revisions;
+	const char *switch_to;
+	int root, root_with_onto;
+	struct object_id *squash_onto;
+	struct commit *restrict_revision;
+	int dont_finish_rebase;
+	enum {
+		REBASE_NO_QUIET = 1<<0,
+		REBASE_VERBOSE = 1<<1,
+		REBASE_DIFFSTAT = 1<<2,
+		REBASE_FORCE = 1<<3,
+		REBASE_INTERACTIVE_EXPLICIT = 1<<4,
+	} flags;
+	struct strvec git_am_opts;
+	enum action action;
+	char *reflog_action;
+	int signoff;
+	int allow_rerere_autoupdate;
+	int keep_empty;
+	int autosquash;
+	char *gpg_sign_opt;
+	int autostash;
+	int committer_date_is_author_date;
+	int ignore_date;
+	char *cmd;
+	int allow_empty_message;
+	int rebase_merges, rebase_cousins;
+	char *strategy, *strategy_opts;
+	struct strbuf git_format_patch_opt;
+	int reschedule_failed_exec;
+	int reapply_cherry_picks;
+	int fork_point;
+	int update_refs;
+};
+
+#define REBASE_OPTIONS_INIT {			  	\
+		.type = REBASE_UNSPECIFIED,	  	\
+		.empty = EMPTY_UNSPECIFIED,	  	\
+		.keep_empty = 1,			\
+		.default_backend = "merge",	  	\
+		.flags = REBASE_NO_QUIET, 		\
+		.git_am_opts = STRVEC_INIT,		\
+		.git_format_patch_opt = STRBUF_INIT,	\
+		.fork_point = -1,			\
+	}
+
+static struct replay_opts get_replay_opts(const struct rebase_options *opts)
+{
+	struct replay_opts replay = REPLAY_OPTS_INIT;
+
+	replay.action = REPLAY_INTERACTIVE_REBASE;
+	replay.strategy = NULL;
+	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.drop_redundant_commits = (opts->empty == EMPTY_DROP);
+	replay.keep_redundant_commits = (opts->empty == EMPTY_KEEP);
+	replay.quiet = !(opts->flags & REBASE_NO_QUIET);
+	replay.verbose = opts->flags & REBASE_VERBOSE;
+	replay.reschedule_failed_exec = opts->reschedule_failed_exec;
+	replay.committer_date_is_author_date =
+					opts->committer_date_is_author_date;
+	replay.ignore_date = opts->ignore_date;
+	replay.gpg_sign = xstrdup_or_null(opts->gpg_sign_opt);
+	replay.reflog_action = xstrdup(opts->reflog_action);
+	if (opts->strategy)
+		replay.strategy = xstrdup_or_null(opts->strategy);
+	else if (!replay.strategy && replay.default_strategy) {
+		replay.strategy = replay.default_strategy;
+		replay.default_strategy = NULL;
+	}
+
+	if (opts->strategy_opts)
+		parse_strategy_opts(&replay, opts->strategy_opts);
+
+	if (opts->squash_onto) {
+		oidcpy(&replay.squash_onto, opts->squash_onto);
+		replay.have_squash_onto = 1;
+	}
+
+	return replay;
+}
+
+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,
+			       struct object_id *orig_head, char **revisions,
+			       char **shortrevisions)
+{
+	struct commit *base_rev = upstream ? upstream : onto;
+	const char *shorthead;
+
+	*revisions = xstrfmt("%s...%s", oid_to_hex(&base_rev->object.oid),
+			     oid_to_hex(orig_head));
+
+	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 struct object_id *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;
+	char *revisions = NULL, *shortrevisions = NULL;
+	struct strvec make_script_args = STRVEC_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 (get_revision_ranges(opts->upstream, opts->onto, &opts->orig_head->object.oid,
+				&revisions, &shortrevisions))
+		return -1;
+
+	if (init_basic_state(&replay,
+			     opts->head_name ? opts->head_name : "detached HEAD",
+			     opts->onto, &opts->orig_head->object.oid)) {
+		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));
+
+	strvec_pushl(&make_script_args, "", revisions, NULL);
+	if (opts->restrict_revision)
+		strvec_pushf(&make_script_args, "^%s",
+			     oid_to_hex(&opts->restrict_revision->object.oid));
+
+	ret = sequencer_make_script(the_repository, &todo_list.buf,
+				    make_script_args.nr, make_script_args.v,
+				    flags);
+
+	if (ret)
+		error(_("could not generate todo list"));
+	else {
+		discard_index(&the_index);
+		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,
+			&opts->orig_head->object.oid, &commands,
+			opts->autosquash, opts->update_refs, &todo_list);
+	}
+
+	string_list_clear(&commands, 0);
+	free(revisions);
+	free(shortrevisions);
+	todo_list_release(&todo_list);
+	strvec_clear(&make_script_args);
+
+	return ret;
+}
+
+static int run_sequencer_rebase(struct rebase_options *opts)
+{
+	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 |= opts->root_with_onto ? TODO_LIST_ROOT_WITH_ONTO : 0;
+	flags |= opts->reapply_cherry_picks ? TODO_LIST_REAPPLY_CHERRY_PICKS : 0;
+	flags |= opts->flags & REBASE_NO_QUIET ? TODO_LIST_WARN_SKIPPED_CHERRY_PICKS : 0;
+
+	switch (opts->action) {
+	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;
+		strvec_pushl(&cmd.args, "show", "REBASE_HEAD", "--", NULL);
+		ret = run_command(&cmd);
+
+		break;
+	}
+	default:
+		BUG("invalid command '%d'", opts->action);
+	}
+
+	return ret;
+}
+
+static void imply_merge(struct rebase_options *opts, const char *option);
+static int parse_opt_keep_empty(const struct option *opt, const char *arg,
+				int unset)
+{
+	struct rebase_options *opts = opt->value;
+
+	BUG_ON_OPT_ARG(arg);
+
+	imply_merge(opts, unset ? "--no-keep-empty" : "--keep-empty");
+	opts->keep_empty = !unset;
+	opts->type = REBASE_MERGE;
+	return 0;
+}
+
+static int is_merge(struct rebase_options *opts)
+{
+	return opts->type == REBASE_MERGE;
+}
+
+static void imply_merge(struct rebase_options *opts, const char *option)
+{
+	switch (opts->type) {
+	case REBASE_APPLY:
+		die(_("%s requires the merge backend"), option);
+		break;
+	case REBASE_MERGE:
+		break;
+	default:
+		opts->type = REBASE_MERGE; /* implied */
+		break;
+	}
+}
+
+/* Returns the filename prefixed by the state_dir */
+static const char *state_dir_path(const char *filename, struct rebase_options *opts)
+{
+	static struct strbuf path = STRBUF_INIT;
+	static size_t prefix_len;
+
+	if (!prefix_len) {
+		strbuf_addf(&path, "%s/", opts->state_dir);
+		prefix_len = path.len;
+	}
+
+	strbuf_setlen(&path, prefix_len);
+	strbuf_addstr(&path, filename);
+	return path.buf;
+}
+
+/* Initialize the rebase options from the state directory. */
+static int read_basic_state(struct rebase_options *opts)
+{
+	struct strbuf head_name = STRBUF_INIT;
+	struct strbuf buf = STRBUF_INIT;
+	struct object_id oid;
+
+	if (!read_oneliner(&head_name, state_dir_path("head-name", opts),
+			   READ_ONELINER_WARN_MISSING) ||
+	    !read_oneliner(&buf, state_dir_path("onto", opts),
+			   READ_ONELINER_WARN_MISSING))
+		return -1;
+	opts->head_name = starts_with(head_name.buf, "refs/") ?
+		xstrdup(head_name.buf) : NULL;
+	strbuf_release(&head_name);
+	if (get_oid_hex(buf.buf, &oid) ||
+	    !(opts->onto = lookup_commit_object(the_repository, &oid)))
+		return error(_("invalid onto: '%s'"), buf.buf);
+
+	/*
+	 * We always write to orig-head, but interactive rebase used to write to
+	 * head. Fall back to reading from head to cover for the case that the
+	 * user upgraded git with an ongoing interactive rebase.
+	 */
+	strbuf_reset(&buf);
+	if (file_exists(state_dir_path("orig-head", opts))) {
+		if (!read_oneliner(&buf, state_dir_path("orig-head", opts),
+				   READ_ONELINER_WARN_MISSING))
+			return -1;
+	} else if (!read_oneliner(&buf, state_dir_path("head", opts),
+				  READ_ONELINER_WARN_MISSING))
+		return -1;
+	if (get_oid_hex(buf.buf, &oid) ||
+	    !(opts->orig_head = lookup_commit_object(the_repository, &oid)))
+		return error(_("invalid orig-head: '%s'"), buf.buf);
+
+	if (file_exists(state_dir_path("quiet", opts)))
+		opts->flags &= ~REBASE_NO_QUIET;
+	else
+		opts->flags |= REBASE_NO_QUIET;
+
+	if (file_exists(state_dir_path("verbose", opts)))
+		opts->flags |= REBASE_VERBOSE;
+
+	if (file_exists(state_dir_path("signoff", opts))) {
+		opts->signoff = 1;
+		opts->flags |= REBASE_FORCE;
+	}
+
+	if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
+		strbuf_reset(&buf);
+		if (!read_oneliner(&buf, state_dir_path("allow_rerere_autoupdate", opts),
+				   READ_ONELINER_WARN_MISSING))
+			return -1;
+		if (!strcmp(buf.buf, "--rerere-autoupdate"))
+			opts->allow_rerere_autoupdate = RERERE_AUTOUPDATE;
+		else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
+			opts->allow_rerere_autoupdate = RERERE_NOAUTOUPDATE;
+		else
+			warning(_("ignoring invalid allow_rerere_autoupdate: "
+				  "'%s'"), buf.buf);
+	}
+
+	if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
+		strbuf_reset(&buf);
+		if (!read_oneliner(&buf, state_dir_path("gpg_sign_opt", opts),
+				   READ_ONELINER_WARN_MISSING))
+			return -1;
+		free(opts->gpg_sign_opt);
+		opts->gpg_sign_opt = xstrdup(buf.buf);
+	}
+
+	if (file_exists(state_dir_path("strategy", opts))) {
+		strbuf_reset(&buf);
+		if (!read_oneliner(&buf, state_dir_path("strategy", opts),
+				   READ_ONELINER_WARN_MISSING))
+			return -1;
+		free(opts->strategy);
+		opts->strategy = xstrdup(buf.buf);
+	}
+
+	if (file_exists(state_dir_path("strategy_opts", opts))) {
+		strbuf_reset(&buf);
+		if (!read_oneliner(&buf, state_dir_path("strategy_opts", opts),
+				   READ_ONELINER_WARN_MISSING))
+			return -1;
+		free(opts->strategy_opts);
+		opts->strategy_opts = xstrdup(buf.buf);
+	}
+
+	strbuf_release(&buf);
+
+	return 0;
+}
+
+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");
+	write_file(state_dir_path("onto", opts), "%s",
+		   opts->onto ? oid_to_hex(&opts->onto->object.oid) : "");
+	write_file(state_dir_path("orig-head", opts), "%s",
+		   oid_to_hex(&opts->orig_head->object.oid));
+	if (!(opts->flags & REBASE_NO_QUIET))
+		write_file(state_dir_path("quiet", opts), "%s", "");
+	if (opts->flags & REBASE_VERBOSE)
+		write_file(state_dir_path("verbose", opts), "%s", "");
+	if (opts->strategy)
+		write_file(state_dir_path("strategy", opts), "%s",
+			   opts->strategy);
+	if (opts->strategy_opts)
+		write_file(state_dir_path("strategy_opts", opts), "%s",
+			   opts->strategy_opts);
+	if (opts->allow_rerere_autoupdate > 0)
+		write_file(state_dir_path("allow_rerere_autoupdate", opts),
+			   "-%s-rerere-autoupdate",
+			   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);
+	if (opts->signoff)
+		write_file(state_dir_path("signoff", opts), "--signoff");
+
+	return 0;
+}
+
+static int finish_rebase(struct rebase_options *opts)
+{
+	struct strbuf dir = STRBUF_INIT;
+	int ret = 0;
+
+	delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
+	unlink(git_path_auto_merge(the_repository));
+	apply_autostash(state_dir_path("autostash", opts));
+	/*
+	 * We ignore errors in 'git maintenance run --auto', since the
+	 * user should see them.
+	 */
+	run_auto_maintenance(!(opts->flags & (REBASE_NO_QUIET|REBASE_VERBOSE)));
+	if (opts->type == REBASE_MERGE) {
+		struct replay_opts replay = REPLAY_OPTS_INIT;
+
+		replay.action = REPLAY_INTERACTIVE_REBASE;
+		ret = sequencer_remove_state(&replay);
+	} else {
+		strbuf_addstr(&dir, opts->state_dir);
+		if (remove_dir_recursively(&dir, 0))
+			ret = error(_("could not remove '%s'"),
+				    opts->state_dir);
+		strbuf_release(&dir);
+	}
+
+	return ret;
+}
+
+static int move_to_original_branch(struct rebase_options *opts)
+{
+	struct strbuf branch_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
+	struct reset_head_opts ropts = { 0 };
+	int ret;
+
+	if (!opts->head_name)
+		return 0; /* nothing to move back to */
+
+	if (!opts->onto)
+		BUG("move_to_original_branch without onto");
+
+	strbuf_addf(&branch_reflog, "%s (finish): %s onto %s",
+		    opts->reflog_action,
+		    opts->head_name, oid_to_hex(&opts->onto->object.oid));
+	strbuf_addf(&head_reflog, "%s (finish): returning to %s",
+		    opts->reflog_action, opts->head_name);
+	ropts.branch = opts->head_name;
+	ropts.flags = RESET_HEAD_REFS_ONLY;
+	ropts.branch_msg = branch_reflog.buf;
+	ropts.head_msg = head_reflog.buf;
+	ret = reset_head(the_repository, &ropts);
+
+	strbuf_release(&branch_reflog);
+	strbuf_release(&head_reflog);
+	return ret;
+}
+
+static const char *resolvemsg =
+N_("Resolve all conflicts manually, mark them as resolved with\n"
+"\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
+"You can instead skip this commit: run \"git rebase --skip\".\n"
+"To abort and get back to the state before \"git rebase\", run "
+"\"git rebase --abort\".");
+
+static int run_am(struct rebase_options *opts)
+{
+	struct child_process am = CHILD_PROCESS_INIT;
+	struct child_process format_patch = CHILD_PROCESS_INIT;
+	struct strbuf revisions = STRBUF_INIT;
+	int status;
+	char *rebased_patches;
+
+	am.git_cmd = 1;
+	strvec_push(&am.args, "am");
+	strvec_pushf(&am.env, GIT_REFLOG_ACTION_ENVIRONMENT "=%s (pick)",
+		     opts->reflog_action);
+	if (opts->action == ACTION_CONTINUE) {
+		strvec_push(&am.args, "--resolved");
+		strvec_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
+		if (opts->gpg_sign_opt)
+			strvec_push(&am.args, opts->gpg_sign_opt);
+		status = run_command(&am);
+		if (status)
+			return status;
+
+		return move_to_original_branch(opts);
+	}
+	if (opts->action == ACTION_SKIP) {
+		strvec_push(&am.args, "--skip");
+		strvec_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
+		status = run_command(&am);
+		if (status)
+			return status;
+
+		return move_to_original_branch(opts);
+	}
+	if (opts->action == ACTION_SHOW_CURRENT_PATCH) {
+		strvec_push(&am.args, "--show-current-patch");
+		return run_command(&am);
+	}
+
+	strbuf_addf(&revisions, "%s...%s",
+		    oid_to_hex(opts->root ?
+			       /* this is now equivalent to !opts->upstream */
+			       &opts->onto->object.oid :
+			       &opts->upstream->object.oid),
+		    oid_to_hex(&opts->orig_head->object.oid));
+
+	rebased_patches = xstrdup(git_path("rebased-patches"));
+	format_patch.out = open(rebased_patches,
+				O_WRONLY | O_CREAT | O_TRUNC, 0666);
+	if (format_patch.out < 0) {
+		status = error_errno(_("could not open '%s' for writing"),
+				     rebased_patches);
+		free(rebased_patches);
+		strvec_clear(&am.args);
+		return status;
+	}
+
+	format_patch.git_cmd = 1;
+	strvec_pushl(&format_patch.args, "format-patch", "-k", "--stdout",
+		     "--full-index", "--cherry-pick", "--right-only",
+		     "--src-prefix=a/", "--dst-prefix=b/", "--no-renames",
+		     "--no-cover-letter", "--pretty=mboxrd", "--topo-order",
+		     "--no-base", NULL);
+	if (opts->git_format_patch_opt.len)
+		strvec_split(&format_patch.args,
+			     opts->git_format_patch_opt.buf);
+	strvec_push(&format_patch.args, revisions.buf);
+	if (opts->restrict_revision)
+		strvec_pushf(&format_patch.args, "^%s",
+			     oid_to_hex(&opts->restrict_revision->object.oid));
+
+	status = run_command(&format_patch);
+	if (status) {
+		struct reset_head_opts ropts = { 0 };
+		unlink(rebased_patches);
+		free(rebased_patches);
+		strvec_clear(&am.args);
+
+		ropts.oid = &opts->orig_head->object.oid;
+		ropts.branch = opts->head_name;
+		ropts.default_reflog_action = opts->reflog_action;
+		reset_head(the_repository, &ropts);
+		error(_("\ngit encountered an error while preparing the "
+			"patches to replay\n"
+			"these revisions:\n"
+			"\n    %s\n\n"
+			"As a result, git cannot rebase them."),
+		      opts->revisions);
+
+		strbuf_release(&revisions);
+		return status;
+	}
+	strbuf_release(&revisions);
+
+	am.in = open(rebased_patches, O_RDONLY);
+	if (am.in < 0) {
+		status = error_errno(_("could not open '%s' for reading"),
+				     rebased_patches);
+		free(rebased_patches);
+		strvec_clear(&am.args);
+		return status;
+	}
+
+	strvec_pushv(&am.args, opts->git_am_opts.v);
+	strvec_push(&am.args, "--rebasing");
+	strvec_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
+	strvec_push(&am.args, "--patch-format=mboxrd");
+	if (opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE)
+		strvec_push(&am.args, "--rerere-autoupdate");
+	else if (opts->allow_rerere_autoupdate == RERERE_NOAUTOUPDATE)
+		strvec_push(&am.args, "--no-rerere-autoupdate");
+	if (opts->gpg_sign_opt)
+		strvec_push(&am.args, opts->gpg_sign_opt);
+	status = run_command(&am);
+	unlink(rebased_patches);
+	free(rebased_patches);
+
+	if (!status) {
+		return move_to_original_branch(opts);
+	}
+
+	if (is_directory(opts->state_dir))
+		rebase_write_basic_state(opts);
+
+	return status;
+}
+
+static int run_specific_rebase(struct rebase_options *opts)
+{
+	int status;
+
+	if (opts->type == REBASE_MERGE) {
+		/* Run sequencer-based rebase */
+		setenv("GIT_CHERRY_PICK_HELP", resolvemsg, 1);
+		if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
+			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;
+		}
+
+		status = run_sequencer_rebase(opts);
+	} else if (opts->type == REBASE_APPLY)
+		status = run_am(opts);
+	else
+		BUG("Unhandled rebase type %d", opts->type);
+
+	if (opts->dont_finish_rebase)
+		; /* do nothing */
+	else if (opts->type == REBASE_MERGE)
+		; /* merge backend cleans up after itself */
+	else if (status == 0) {
+		if (!file_exists(state_dir_path("stopped-sha", opts)))
+			finish_rebase(opts);
+	} else if (status == 2) {
+		struct strbuf dir = STRBUF_INIT;
+
+		apply_autostash(state_dir_path("autostash", opts));
+		strbuf_addstr(&dir, opts->state_dir);
+		remove_dir_recursively(&dir, 0);
+		strbuf_release(&dir);
+		die("Nothing to do");
+	}
+
+	return status ? -1 : 0;
+}
+
+static int rebase_config(const char *var, const char *value, void *data)
+{
+	struct rebase_options *opts = data;
+
+	if (!strcmp(var, "rebase.stat")) {
+		if (git_config_bool(var, value))
+			opts->flags |= REBASE_DIFFSTAT;
+		else
+			opts->flags &= ~REBASE_DIFFSTAT;
+		return 0;
+	}
+
+	if (!strcmp(var, "rebase.autosquash")) {
+		opts->autosquash = git_config_bool(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "commit.gpgsign")) {
+		free(opts->gpg_sign_opt);
+		opts->gpg_sign_opt = git_config_bool(var, value) ?
+			xstrdup("-S") : NULL;
+		return 0;
+	}
+
+	if (!strcmp(var, "rebase.autostash")) {
+		opts->autostash = git_config_bool(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "rebase.updaterefs")) {
+		opts->update_refs = git_config_bool(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "rebase.reschedulefailedexec")) {
+		opts->reschedule_failed_exec = git_config_bool(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "rebase.forkpoint")) {
+		opts->fork_point = git_config_bool(var, value) ? -1 : 0;
+		return 0;
+	}
+
+	if (!strcmp(var, "rebase.backend")) {
+		return git_config_string(&opts->default_backend, var, value);
+	}
+
+	return git_default_config(var, value, data);
+}
+
+static int checkout_up_to_date(struct rebase_options *options)
+{
+	struct strbuf buf = STRBUF_INIT;
+	struct reset_head_opts ropts = { 0 };
+	int ret = 0;
+
+	strbuf_addf(&buf, "%s: checkout %s",
+		    options->reflog_action, options->switch_to);
+	ropts.oid = &options->orig_head->object.oid;
+	ropts.branch = options->head_name;
+	ropts.flags = RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
+	if (!ropts.branch)
+		ropts.flags |=  RESET_HEAD_DETACH;
+	ropts.head_msg = buf.buf;
+	if (reset_head(the_repository, &ropts) < 0)
+		ret = error(_("could not switch to %s"), options->switch_to);
+	strbuf_release(&buf);
+
+	return ret;
+}
+
+/*
+ * Determines whether the commits in from..to are linear, i.e. contain
+ * no merge commits. This function *expects* `from` to be an ancestor of
+ * `to`.
+ */
+static int is_linear_history(struct commit *from, struct commit *to)
+{
+	while (to && to != from) {
+		parse_commit(to);
+		if (!to->parents)
+			return 1;
+		if (to->parents->next)
+			return 0;
+		to = to->parents->item;
+	}
+	return 1;
+}
+
+static int can_fast_forward(struct commit *onto, struct commit *upstream,
+			    struct commit *restrict_revision,
+			    struct commit *head, struct object_id *branch_base)
+{
+	struct commit_list *merge_bases = NULL;
+	int res = 0;
+
+	if (is_null_oid(branch_base))
+		goto done; /* fill_branch_base() found multiple merge bases */
+
+	if (!oideq(branch_base, &onto->object.oid))
+		goto done;
+
+	if (restrict_revision && !oideq(&restrict_revision->object.oid, branch_base))
+		goto done;
+
+	if (!upstream)
+		goto done;
+
+	merge_bases = get_merge_bases(upstream, head);
+	if (!merge_bases || merge_bases->next)
+		goto done;
+
+	if (!oideq(&onto->object.oid, &merge_bases->item->object.oid))
+		goto done;
+
+	res = 1;
+
+done:
+	free_commit_list(merge_bases);
+	return res && is_linear_history(onto, head);
+}
+
+static void fill_branch_base(struct rebase_options *options,
+			    struct object_id *branch_base)
+{
+	struct commit_list *merge_bases = NULL;
+
+	merge_bases = get_merge_bases(options->onto, options->orig_head);
+	if (!merge_bases || merge_bases->next)
+		oidcpy(branch_base, null_oid());
+	else
+		oidcpy(branch_base, &merge_bases->item->object.oid);
+
+	free_commit_list(merge_bases);
+}
+
+static int parse_opt_am(const struct option *opt, const char *arg, int unset)
+{
+	struct rebase_options *opts = opt->value;
+
+	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
+
+	opts->type = REBASE_APPLY;
+
+	return 0;
+}
+
+/* -i followed by -m is still -i */
+static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
+{
+	struct rebase_options *opts = opt->value;
+
+	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
+
+	if (!is_merge(opts))
+		opts->type = REBASE_MERGE;
+
+	return 0;
+}
+
+/* -i followed by -r is still explicitly interactive, but -r alone is not */
+static int parse_opt_interactive(const struct option *opt, const char *arg,
+				 int unset)
+{
+	struct rebase_options *opts = opt->value;
+
+	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
+
+	opts->type = REBASE_MERGE;
+	opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
+
+	return 0;
+}
+
+static enum empty_type parse_empty_value(const char *value)
+{
+	if (!strcasecmp(value, "drop"))
+		return EMPTY_DROP;
+	else if (!strcasecmp(value, "keep"))
+		return EMPTY_KEEP;
+	else if (!strcasecmp(value, "ask"))
+		return EMPTY_ASK;
+
+	die(_("unrecognized empty type '%s'; valid values are \"drop\", \"keep\", and \"ask\"."), value);
+}
+
+static int parse_opt_empty(const struct option *opt, const char *arg, int unset)
+{
+	struct rebase_options *options = opt->value;
+	enum empty_type value = parse_empty_value(arg);
+
+	BUG_ON_OPT_NEG(unset);
+
+	options->empty = value;
+	return 0;
+}
+
+static void NORETURN error_on_missing_default_upstream(void)
+{
+	struct branch *current_branch = branch_get(NULL);
+
+	printf(_("%s\n"
+		 "Please specify which branch you want to rebase against.\n"
+		 "See git-rebase(1) for details.\n"
+		 "\n"
+		 "    git rebase '<branch>'\n"
+		 "\n"),
+		current_branch ? _("There is no tracking information for "
+			"the current branch.") :
+			_("You are not currently on a branch."));
+
+	if (current_branch) {
+		const char *remote = current_branch->remote_name;
+
+		if (!remote)
+			remote = _("<remote>");
+
+		printf(_("If you wish to set tracking information for this "
+			 "branch you can do so with:\n"
+			 "\n"
+			 "    git branch --set-upstream-to=%s/<branch> %s\n"
+			 "\n"),
+		       remote, current_branch->name);
+	}
+	exit(1);
+}
+
+static int check_exec_cmd(const char *cmd)
+{
+	if (strchr(cmd, '\n'))
+		return error(_("exec commands cannot contain newlines"));
+
+	/* Does the command consist purely of whitespace? */
+	if (!cmd[strspn(cmd, " \t\r\f\v")])
+		return error(_("empty exec command"));
+
+	return 0;
+}
+
+int cmd_rebase(int argc, const char **argv, const char *prefix)
+{
+	struct rebase_options options = REBASE_OPTIONS_INIT;
+	const char *branch_name;
+	int ret, flags, total_argc, in_progress = 0;
+	int keep_base = 0;
+	int ok_to_skip_pre_rebase = 0;
+	struct strbuf msg = STRBUF_INIT;
+	struct strbuf revisions = STRBUF_INIT;
+	struct strbuf buf = STRBUF_INIT;
+	struct object_id branch_base;
+	int ignore_whitespace = 0;
+	const char *gpg_sign = NULL;
+	struct string_list exec = STRING_LIST_INIT_NODUP;
+	const char *rebase_merges = NULL;
+	struct string_list strategy_options = STRING_LIST_INIT_NODUP;
+	struct object_id squash_onto;
+	char *squash_onto_name = NULL;
+	int reschedule_failed_exec = -1;
+	int allow_preemptive_ff = 1;
+	int preserve_merges_selected = 0;
+	struct reset_head_opts ropts = { 0 };
+	struct option builtin_rebase_options[] = {
+		OPT_STRING(0, "onto", &options.onto_name,
+			   N_("revision"),
+			   N_("rebase onto given branch instead of upstream")),
+		OPT_BOOL(0, "keep-base", &keep_base,
+			 N_("use the merge-base of upstream and branch as the current base")),
+		OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
+			 N_("allow pre-rebase hook to run")),
+		OPT_NEGBIT('q', "quiet", &options.flags,
+			   N_("be quiet. implies --no-stat"),
+			   REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
+		OPT_BIT('v', "verbose", &options.flags,
+			N_("display a diffstat of what changed upstream"),
+			REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
+		{OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
+			N_("do not show diffstat of what changed upstream"),
+			PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
+		OPT_BOOL(0, "signoff", &options.signoff,
+			 N_("add a Signed-off-by trailer to each commit")),
+		OPT_BOOL(0, "committer-date-is-author-date",
+			 &options.committer_date_is_author_date,
+			 N_("make committer date match author date")),
+		OPT_BOOL(0, "reset-author-date", &options.ignore_date,
+			 N_("ignore author date and use current date")),
+		OPT_HIDDEN_BOOL(0, "ignore-date", &options.ignore_date,
+				N_("synonym of --reset-author-date")),
+		OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
+				  N_("passed to 'git apply'"), 0),
+		OPT_BOOL(0, "ignore-whitespace", &ignore_whitespace,
+			 N_("ignore changes in whitespace")),
+		OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
+				  N_("action"), N_("passed to 'git apply'"), 0),
+		OPT_BIT('f', "force-rebase", &options.flags,
+			N_("cherry-pick all commits, even if unchanged"),
+			REBASE_FORCE),
+		OPT_BIT(0, "no-ff", &options.flags,
+			N_("cherry-pick all commits, even if unchanged"),
+			REBASE_FORCE),
+		OPT_CMDMODE(0, "continue", &options.action, N_("continue"),
+			    ACTION_CONTINUE),
+		OPT_CMDMODE(0, "skip", &options.action,
+			    N_("skip current patch and continue"), ACTION_SKIP),
+		OPT_CMDMODE(0, "abort", &options.action,
+			    N_("abort and check out the original branch"),
+			    ACTION_ABORT),
+		OPT_CMDMODE(0, "quit", &options.action,
+			    N_("abort but keep HEAD where it is"), ACTION_QUIT),
+		OPT_CMDMODE(0, "edit-todo", &options.action, N_("edit the todo list "
+			    "during an interactive rebase"), ACTION_EDIT_TODO),
+		OPT_CMDMODE(0, "show-current-patch", &options.action,
+			    N_("show the patch file being applied or merged"),
+			    ACTION_SHOW_CURRENT_PATCH),
+		OPT_CALLBACK_F(0, "apply", &options, NULL,
+			N_("use apply strategies to rebase"),
+			PARSE_OPT_NOARG | PARSE_OPT_NONEG,
+			parse_opt_am),
+		OPT_CALLBACK_F('m', "merge", &options, NULL,
+			N_("use merging strategies to rebase"),
+			PARSE_OPT_NOARG | PARSE_OPT_NONEG,
+			parse_opt_merge),
+		OPT_CALLBACK_F('i', "interactive", &options, NULL,
+			N_("let the user edit the list of commits to rebase"),
+			PARSE_OPT_NOARG | PARSE_OPT_NONEG,
+			parse_opt_interactive),
+		OPT_SET_INT_F('p', "preserve-merges", &preserve_merges_selected,
+			      N_("(REMOVED) was: try to recreate merges "
+				 "instead of ignoring them"),
+			      1, PARSE_OPT_HIDDEN),
+		OPT_RERERE_AUTOUPDATE(&options.allow_rerere_autoupdate),
+		OPT_CALLBACK_F(0, "empty", &options, "{drop,keep,ask}",
+			       N_("how to handle commits that become empty"),
+			       PARSE_OPT_NONEG, parse_opt_empty),
+		OPT_CALLBACK_F('k', "keep-empty", &options, NULL,
+			N_("keep commits which start empty"),
+			PARSE_OPT_NOARG | PARSE_OPT_HIDDEN,
+			parse_opt_keep_empty),
+		OPT_BOOL(0, "autosquash", &options.autosquash,
+			 N_("move commits that begin with "
+			    "squash!/fixup! under -i")),
+		OPT_BOOL(0, "update-refs", &options.update_refs,
+			 N_("update branches that point to commits "
+			    "that are being rebased")),
+		{ OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
+			N_("GPG-sign commits"),
+			PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
+		OPT_AUTOSTASH(&options.autostash),
+		OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
+				N_("add exec lines after each commit of the "
+				   "editable list")),
+		OPT_BOOL_F(0, "allow-empty-message",
+			   &options.allow_empty_message,
+			   N_("allow rebasing commits with empty messages"),
+			   PARSE_OPT_HIDDEN),
+		{OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
+			N_("mode"),
+			N_("try to rebase merges instead of skipping them"),
+			PARSE_OPT_OPTARG, NULL, (intptr_t)""},
+		OPT_BOOL(0, "fork-point", &options.fork_point,
+			 N_("use 'merge-base --fork-point' to refine upstream")),
+		OPT_STRING('s', "strategy", &options.strategy,
+			   N_("strategy"), N_("use the given merge strategy")),
+		OPT_STRING_LIST('X', "strategy-option", &strategy_options,
+				N_("option"),
+				N_("pass the argument through to the merge "
+				   "strategy")),
+		OPT_BOOL(0, "root", &options.root,
+			 N_("rebase all reachable commits up to the root(s)")),
+		OPT_BOOL(0, "reschedule-failed-exec",
+			 &reschedule_failed_exec,
+			 N_("automatically re-schedule any `exec` that fails")),
+		OPT_BOOL(0, "reapply-cherry-picks", &options.reapply_cherry_picks,
+			 N_("apply all changes, even those already present upstream")),
+		OPT_END(),
+	};
+	int i;
+
+	if (argc == 2 && !strcmp(argv[1], "-h"))
+		usage_with_options(builtin_rebase_usage,
+				   builtin_rebase_options);
+
+	prepare_repo_settings(the_repository);
+	the_repository->settings.command_requires_full_index = 0;
+
+	options.reapply_cherry_picks = -1;
+	options.allow_empty_message = 1;
+	git_config(rebase_config, &options);
+	/* options.gpg_sign_opt will be either "-S" or NULL */
+	gpg_sign = options.gpg_sign_opt ? "" : NULL;
+	FREE_AND_NULL(options.gpg_sign_opt);
+
+	strbuf_reset(&buf);
+	strbuf_addf(&buf, "%s/applying", apply_dir());
+	if(file_exists(buf.buf))
+		die(_("It looks like 'git am' is in progress. Cannot rebase."));
+
+	if (is_directory(apply_dir())) {
+		options.type = REBASE_APPLY;
+		options.state_dir = apply_dir();
+	} else if (is_directory(merge_dir())) {
+		strbuf_reset(&buf);
+		strbuf_addf(&buf, "%s/rewritten", merge_dir());
+		if (!(options.action == ACTION_ABORT) && is_directory(buf.buf)) {
+			die(_("`rebase --preserve-merges` (-p) is no longer supported.\n"
+			"Use `git rebase --abort` to terminate current rebase.\n"
+			"Or downgrade to v2.33, or earlier, to complete the rebase."));
+		} else {
+			strbuf_reset(&buf);
+			strbuf_addf(&buf, "%s/interactive", merge_dir());
+			options.type = REBASE_MERGE;
+			if (file_exists(buf.buf))
+				options.flags |= REBASE_INTERACTIVE_EXPLICIT;
+		}
+		options.state_dir = merge_dir();
+	}
+
+	if (options.type != REBASE_UNSPECIFIED)
+		in_progress = 1;
+
+	total_argc = argc;
+	argc = parse_options(argc, argv, prefix,
+			     builtin_rebase_options,
+			     builtin_rebase_usage, 0);
+
+	if (preserve_merges_selected)
+		die(_("--preserve-merges was replaced by --rebase-merges\n"
+			"Note: Your `pull.rebase` configuration may also be set to 'preserve',\n"
+			"which is no longer supported; use 'merges' instead"));
+
+	if (options.action != ACTION_NONE && total_argc != 2) {
+		usage_with_options(builtin_rebase_usage,
+				   builtin_rebase_options);
+	}
+
+	if (argc > 2)
+		usage_with_options(builtin_rebase_usage,
+				   builtin_rebase_options);
+
+	if (keep_base) {
+		if (options.onto_name)
+			die(_("options '%s' and '%s' cannot be used together"), "--keep-base", "--onto");
+		if (options.root)
+			die(_("options '%s' and '%s' cannot be used together"), "--keep-base", "--root");
+		/*
+		 * --keep-base defaults to --no-fork-point to keep the
+		 * base the same.
+		 */
+		if (options.fork_point < 0)
+			options.fork_point = 0;
+	}
+	/*
+	 * --keep-base defaults to --reapply-cherry-picks to avoid losing
+	 * commits when using this option.
+	 */
+	if (options.reapply_cherry_picks < 0)
+		options.reapply_cherry_picks = keep_base;
+
+	if (options.root && options.fork_point > 0)
+		die(_("options '%s' and '%s' cannot be used together"), "--root", "--fork-point");
+
+	if (options.action != ACTION_NONE && !in_progress)
+		die(_("No rebase in progress?"));
+
+	if (options.action == ACTION_EDIT_TODO && !is_merge(&options))
+		die(_("The --edit-todo action can only be used during "
+		      "interactive rebase."));
+
+	if (trace2_is_enabled()) {
+		if (is_merge(&options))
+			trace2_cmd_mode("interactive");
+		else if (exec.nr)
+			trace2_cmd_mode("interactive-exec");
+		else
+			trace2_cmd_mode(action_names[options.action]);
+	}
+
+	options.reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
+	options.reflog_action =
+		xstrdup(options.reflog_action ? options.reflog_action : "rebase");
+
+	switch (options.action) {
+	case ACTION_CONTINUE: {
+		struct object_id head;
+		struct lock_file lock_file = LOCK_INIT;
+		int fd;
+
+		/* Sanity check */
+		if (get_oid("HEAD", &head))
+			die(_("Cannot read HEAD"));
+
+		fd = repo_hold_locked_index(the_repository, &lock_file, 0);
+		if (repo_read_index(the_repository) < 0)
+			die(_("could not read index"));
+		refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
+			      NULL);
+		if (0 <= fd)
+			repo_update_index_if_able(the_repository, &lock_file);
+		rollback_lock_file(&lock_file);
+
+		if (has_unstaged_changes(the_repository, 1)) {
+			puts(_("You must edit all merge conflicts and then\n"
+			       "mark them as resolved using git add"));
+			exit(1);
+		}
+		if (read_basic_state(&options))
+			exit(1);
+		goto run_rebase;
+	}
+	case ACTION_SKIP: {
+		struct string_list merge_rr = STRING_LIST_INIT_DUP;
+
+		rerere_clear(the_repository, &merge_rr);
+		string_list_clear(&merge_rr, 1);
+		ropts.flags = RESET_HEAD_HARD;
+		if (reset_head(the_repository, &ropts) < 0)
+			die(_("could not discard worktree changes"));
+		remove_branch_state(the_repository, 0);
+		if (read_basic_state(&options))
+			exit(1);
+		goto run_rebase;
+	}
+	case ACTION_ABORT: {
+		struct string_list merge_rr = STRING_LIST_INIT_DUP;
+		struct strbuf head_msg = STRBUF_INIT;
+
+		rerere_clear(the_repository, &merge_rr);
+		string_list_clear(&merge_rr, 1);
+
+		if (read_basic_state(&options))
+			exit(1);
+
+		strbuf_addf(&head_msg, "%s (abort): returning to %s",
+			    options.reflog_action,
+			    options.head_name ? options.head_name
+					      : oid_to_hex(&options.orig_head->object.oid));
+		ropts.oid = &options.orig_head->object.oid;
+		ropts.head_msg = head_msg.buf;
+		ropts.branch = options.head_name;
+		ropts.flags = RESET_HEAD_HARD;
+		if (reset_head(the_repository, &ropts) < 0)
+			die(_("could not move back to %s"),
+			    oid_to_hex(&options.orig_head->object.oid));
+		remove_branch_state(the_repository, 0);
+		ret = finish_rebase(&options);
+		goto cleanup;
+	}
+	case ACTION_QUIT: {
+		save_autostash(state_dir_path("autostash", &options));
+		if (options.type == REBASE_MERGE) {
+			struct replay_opts replay = REPLAY_OPTS_INIT;
+
+			replay.action = REPLAY_INTERACTIVE_REBASE;
+			ret = sequencer_remove_state(&replay);
+		} else {
+			strbuf_reset(&buf);
+			strbuf_addstr(&buf, options.state_dir);
+			ret = remove_dir_recursively(&buf, 0);
+			if (ret)
+				error(_("could not remove '%s'"),
+				       options.state_dir);
+		}
+		goto cleanup;
+	}
+	case ACTION_EDIT_TODO:
+		options.dont_finish_rebase = 1;
+		goto run_rebase;
+	case ACTION_SHOW_CURRENT_PATCH:
+		options.dont_finish_rebase = 1;
+		goto run_rebase;
+	case ACTION_NONE:
+		break;
+	default:
+		BUG("action: %d", options.action);
+	}
+
+	/* Make sure no rebase is in progress */
+	if (in_progress) {
+		const char *last_slash = strrchr(options.state_dir, '/');
+		const char *state_dir_base =
+			last_slash ? last_slash + 1 : options.state_dir;
+		const char *cmd_live_rebase =
+			"git rebase (--continue | --abort | --skip)";
+		strbuf_reset(&buf);
+		strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
+		die(_("It seems that there is already a %s directory, and\n"
+		      "I wonder if you are in the middle of another rebase.  "
+		      "If that is the\n"
+		      "case, please try\n\t%s\n"
+		      "If that is not the case, please\n\t%s\n"
+		      "and run me again.  I am stopping in case you still "
+		      "have something\n"
+		      "valuable there.\n"),
+		    state_dir_base, cmd_live_rebase, buf.buf);
+	}
+
+	if ((options.flags & REBASE_INTERACTIVE_EXPLICIT) ||
+	    (options.action != ACTION_NONE) ||
+	    (exec.nr > 0) ||
+	    options.autosquash) {
+		allow_preemptive_ff = 0;
+	}
+	if (options.committer_date_is_author_date || options.ignore_date)
+		options.flags |= REBASE_FORCE;
+
+	for (i = 0; i < options.git_am_opts.nr; i++) {
+		const char *option = options.git_am_opts.v[i], *p;
+		if (!strcmp(option, "--whitespace=fix") ||
+		    !strcmp(option, "--whitespace=strip"))
+			allow_preemptive_ff = 0;
+		else if (skip_prefix(option, "-C", &p)) {
+			while (*p)
+				if (!isdigit(*(p++)))
+					die(_("switch `C' expects a "
+					      "numerical value"));
+		} else if (skip_prefix(option, "--whitespace=", &p)) {
+			if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
+			    strcmp(p, "error") && strcmp(p, "error-all"))
+				die("Invalid whitespace option: '%s'", p);
+		}
+	}
+
+	for (i = 0; i < exec.nr; i++)
+		if (check_exec_cmd(exec.items[i].string))
+			exit(1);
+
+	if (!(options.flags & REBASE_NO_QUIET))
+		strvec_push(&options.git_am_opts, "-q");
+
+	if (options.empty != EMPTY_UNSPECIFIED)
+		imply_merge(&options, "--empty");
+
+	/*
+	 * --keep-base implements --reapply-cherry-picks by altering upstream so
+	 * it works with both backends.
+	 */
+	if (options.reapply_cherry_picks && !keep_base)
+		imply_merge(&options, "--reapply-cherry-picks");
+
+	if (gpg_sign)
+		options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
+
+	if (exec.nr) {
+		int i;
+
+		imply_merge(&options, "--exec");
+
+		strbuf_reset(&buf);
+		for (i = 0; i < exec.nr; i++)
+			strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
+		options.cmd = xstrdup(buf.buf);
+	}
+
+	if (rebase_merges) {
+		if (!*rebase_merges)
+			; /* default mode; do nothing */
+		else if (!strcmp("rebase-cousins", rebase_merges))
+			options.rebase_cousins = 1;
+		else if (strcmp("no-rebase-cousins", rebase_merges))
+			die(_("Unknown mode: %s"), rebase_merges);
+		options.rebase_merges = 1;
+		imply_merge(&options, "--rebase-merges");
+	}
+
+	if (options.type == REBASE_APPLY) {
+		if (ignore_whitespace)
+			strvec_push(&options.git_am_opts,
+				    "--ignore-whitespace");
+		if (options.committer_date_is_author_date)
+			strvec_push(&options.git_am_opts,
+				    "--committer-date-is-author-date");
+		if (options.ignore_date)
+			strvec_push(&options.git_am_opts, "--ignore-date");
+	} else {
+		/* REBASE_MERGE */
+		if (ignore_whitespace) {
+			string_list_append(&strategy_options,
+					   "ignore-space-change");
+		}
+	}
+
+	if (strategy_options.nr) {
+		int i;
+
+		if (!options.strategy)
+			options.strategy = "ort";
+
+		strbuf_reset(&buf);
+		for (i = 0; i < strategy_options.nr; i++)
+			strbuf_addf(&buf, " --%s",
+				    strategy_options.items[i].string);
+		options.strategy_opts = xstrdup(buf.buf);
+	}
+
+	if (options.strategy) {
+		options.strategy = xstrdup(options.strategy);
+		switch (options.type) {
+		case REBASE_APPLY:
+			die(_("--strategy requires --merge or --interactive"));
+		case REBASE_MERGE:
+			/* compatible */
+			break;
+		case REBASE_UNSPECIFIED:
+			options.type = REBASE_MERGE;
+			break;
+		default:
+			BUG("unhandled rebase type (%d)", options.type);
+		}
+	}
+
+	if (options.type == REBASE_MERGE)
+		imply_merge(&options, "--merge");
+
+	if (options.root && !options.onto_name)
+		imply_merge(&options, "--root without --onto");
+
+	if (isatty(2) && options.flags & REBASE_NO_QUIET)
+		strbuf_addstr(&options.git_format_patch_opt, " --progress");
+
+	if (options.git_am_opts.nr || options.type == REBASE_APPLY) {
+		/* all am options except -q are compatible only with --apply */
+		for (i = options.git_am_opts.nr - 1; i >= 0; i--)
+			if (strcmp(options.git_am_opts.v[i], "-q"))
+				break;
+
+		if (i >= 0) {
+			if (is_merge(&options))
+				die(_("apply options and merge options "
+					  "cannot be used together"));
+			else
+				options.type = REBASE_APPLY;
+		}
+	}
+
+	if (options.type == REBASE_UNSPECIFIED) {
+		if (!strcmp(options.default_backend, "merge"))
+			imply_merge(&options, "--merge");
+		else if (!strcmp(options.default_backend, "apply"))
+			options.type = REBASE_APPLY;
+		else
+			die(_("Unknown rebase backend: %s"),
+			    options.default_backend);
+	}
+
+	if (options.type == REBASE_MERGE &&
+	    !options.strategy &&
+	    getenv("GIT_TEST_MERGE_ALGORITHM"))
+		options.strategy = xstrdup(getenv("GIT_TEST_MERGE_ALGORITHM"));
+
+	switch (options.type) {
+	case REBASE_MERGE:
+		options.state_dir = merge_dir();
+		break;
+	case REBASE_APPLY:
+		options.state_dir = apply_dir();
+		break;
+	default:
+		BUG("options.type was just set above; should be unreachable.");
+	}
+
+	if (options.empty == EMPTY_UNSPECIFIED) {
+		if (options.flags & REBASE_INTERACTIVE_EXPLICIT)
+			options.empty = EMPTY_ASK;
+		else if (exec.nr > 0)
+			options.empty = EMPTY_KEEP;
+		else
+			options.empty = EMPTY_DROP;
+	}
+	if (reschedule_failed_exec > 0 && !is_merge(&options))
+		die(_("--reschedule-failed-exec requires "
+		      "--exec or --interactive"));
+	if (reschedule_failed_exec >= 0)
+		options.reschedule_failed_exec = reschedule_failed_exec;
+
+	if (options.signoff) {
+		strvec_push(&options.git_am_opts, "--signoff");
+		options.flags |= REBASE_FORCE;
+	}
+
+	if (!options.root) {
+		if (argc < 1) {
+			struct branch *branch;
+
+			branch = branch_get(NULL);
+			options.upstream_name = branch_get_upstream(branch,
+								    NULL);
+			if (!options.upstream_name)
+				error_on_missing_default_upstream();
+			if (options.fork_point < 0)
+				options.fork_point = 1;
+		} else {
+			options.upstream_name = argv[0];
+			argc--;
+			argv++;
+			if (!strcmp(options.upstream_name, "-"))
+				options.upstream_name = "@{-1}";
+		}
+		options.upstream =
+			lookup_commit_reference_by_name(options.upstream_name);
+		if (!options.upstream)
+			die(_("invalid upstream '%s'"), options.upstream_name);
+		options.upstream_arg = options.upstream_name;
+	} else {
+		if (!options.onto_name) {
+			if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
+					&squash_onto, NULL, NULL) < 0)
+				die(_("Could not create new root commit"));
+			options.squash_onto = &squash_onto;
+			options.onto_name = squash_onto_name =
+				xstrdup(oid_to_hex(&squash_onto));
+		} else
+			options.root_with_onto = 1;
+
+		options.upstream_name = NULL;
+		options.upstream = NULL;
+		if (argc > 1)
+			usage_with_options(builtin_rebase_usage,
+					   builtin_rebase_options);
+		options.upstream_arg = "--root";
+	}
+
+	/*
+	 * If the branch to rebase is given, that is the branch we will rebase
+	 * branch_name -- branch/commit being rebased, or
+	 * 		  HEAD (already detached)
+	 * orig_head -- commit object name of tip of the branch before rebasing
+	 * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
+	 */
+	if (argc == 1) {
+		/* Is it "rebase other branchname" or "rebase other commit"? */
+		struct object_id branch_oid;
+		branch_name = argv[0];
+		options.switch_to = argv[0];
+
+		/* Is it a local branch? */
+		strbuf_reset(&buf);
+		strbuf_addf(&buf, "refs/heads/%s", branch_name);
+		if (!read_ref(buf.buf, &branch_oid)) {
+			die_if_checked_out(buf.buf, 1);
+			options.head_name = xstrdup(buf.buf);
+			options.orig_head =
+				lookup_commit_object(the_repository,
+						     &branch_oid);
+		/* If not is it a valid ref (branch or commit)? */
+		} else {
+			options.orig_head =
+				lookup_commit_reference_by_name(branch_name);
+			options.head_name = NULL;
+		}
+		if (!options.orig_head)
+			die(_("no such branch/commit '%s'"), branch_name);
+	} else if (argc == 0) {
+		/* Do not need to switch branches, we are already on it. */
+		options.head_name =
+			xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
+					 &flags));
+		if (!options.head_name)
+			die(_("No such ref: %s"), "HEAD");
+		if (flags & REF_ISSYMREF) {
+			if (!skip_prefix(options.head_name,
+					 "refs/heads/", &branch_name))
+				branch_name = options.head_name;
+
+		} else {
+			FREE_AND_NULL(options.head_name);
+			branch_name = "HEAD";
+		}
+		options.orig_head = lookup_commit_reference_by_name("HEAD");
+		if (!options.orig_head)
+			die(_("Could not resolve HEAD to a commit"));
+	} else
+		BUG("unexpected number of arguments left to parse");
+
+	/* Make sure the branch to rebase onto is valid. */
+	if (keep_base) {
+		strbuf_reset(&buf);
+		strbuf_addstr(&buf, options.upstream_name);
+		strbuf_addstr(&buf, "...");
+		strbuf_addstr(&buf, branch_name);
+		options.onto_name = xstrdup(buf.buf);
+	} else if (!options.onto_name)
+		options.onto_name = options.upstream_name;
+	if (strstr(options.onto_name, "...")) {
+		if (get_oid_mb(options.onto_name, &branch_base) < 0) {
+			if (keep_base)
+				die(_("'%s': need exactly one merge base with branch"),
+				    options.upstream_name);
+			else
+				die(_("'%s': need exactly one merge base"),
+				    options.onto_name);
+		}
+		options.onto = lookup_commit_or_die(&branch_base,
+						    options.onto_name);
+	} else {
+		options.onto =
+			lookup_commit_reference_by_name(options.onto_name);
+		if (!options.onto)
+			die(_("Does not point to a valid commit '%s'"),
+				options.onto_name);
+		fill_branch_base(&options, &branch_base);
+	}
+
+	if (keep_base && options.reapply_cherry_picks)
+		options.upstream = options.onto;
+
+	if (options.fork_point > 0)
+		options.restrict_revision =
+			get_fork_point(options.upstream_name, options.orig_head);
+
+	if (repo_read_index(the_repository) < 0)
+		die(_("could not read index"));
+
+	if (options.autostash)
+		create_autostash(the_repository,
+				 state_dir_path("autostash", &options));
+
+
+	if (require_clean_work_tree(the_repository, "rebase",
+				    _("Please commit or stash them."), 1, 1)) {
+		ret = -1;
+		goto cleanup;
+	}
+
+	/*
+	 * Now we are rebasing commits upstream..orig_head (or with --root,
+	 * everything leading up to orig_head) on top of onto.
+	 */
+
+	/*
+	 * Check if we are already based on onto with linear history,
+	 * in which case we could fast-forward without replacing the commits
+	 * with new commits recreated by replaying their changes.
+	 */
+	if (allow_preemptive_ff &&
+	    can_fast_forward(options.onto, options.upstream, options.restrict_revision,
+			     options.orig_head, &branch_base)) {
+		int flag;
+
+		if (!(options.flags & REBASE_FORCE)) {
+			/* Lazily switch to the target branch if needed... */
+			if (options.switch_to) {
+				ret = checkout_up_to_date(&options);
+				if (ret)
+					goto cleanup;
+			}
+
+			if (!(options.flags & REBASE_NO_QUIET))
+				; /* be quiet */
+			else if (!strcmp(branch_name, "HEAD") &&
+				 resolve_ref_unsafe("HEAD", 0, NULL, &flag))
+				puts(_("HEAD is up to date."));
+			else
+				printf(_("Current branch %s is up to date.\n"),
+				       branch_name);
+			ret = finish_rebase(&options);
+			goto cleanup;
+		} else if (!(options.flags & REBASE_NO_QUIET))
+			; /* be quiet */
+		else if (!strcmp(branch_name, "HEAD") &&
+			 resolve_ref_unsafe("HEAD", 0, NULL, &flag))
+			puts(_("HEAD is up to date, rebase forced."));
+		else
+			printf(_("Current branch %s is up to date, rebase "
+				 "forced.\n"), branch_name);
+	}
+
+	/* If a hook exists, give it a chance to interrupt*/
+	if (!ok_to_skip_pre_rebase &&
+	    run_hooks_l("pre-rebase", options.upstream_arg,
+			argc ? argv[0] : NULL, NULL))
+		die(_("The pre-rebase hook refused to rebase."));
+
+	if (options.flags & REBASE_DIFFSTAT) {
+		struct diff_options opts;
+
+		if (options.flags & REBASE_VERBOSE) {
+			if (is_null_oid(&branch_base))
+				printf(_("Changes to %s:\n"),
+				       oid_to_hex(&options.onto->object.oid));
+			else
+				printf(_("Changes from %s to %s:\n"),
+				       oid_to_hex(&branch_base),
+				       oid_to_hex(&options.onto->object.oid));
+		}
+
+		/* We want color (if set), but no pager */
+		diff_setup(&opts);
+		opts.stat_width = -1; /* use full terminal width */
+		opts.stat_graph_width = -1; /* respect statGraphWidth config */
+		opts.output_format |=
+			DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
+		opts.detect_rename = DIFF_DETECT_RENAME;
+		diff_setup_done(&opts);
+		diff_tree_oid(is_null_oid(&branch_base) ?
+			      the_hash_algo->empty_tree : &branch_base,
+			      &options.onto->object.oid, "", &opts);
+		diffcore_std(&opts);
+		diff_flush(&opts);
+	}
+
+	if (is_merge(&options))
+		goto run_rebase;
+
+	/* Detach HEAD and reset the tree */
+	if (options.flags & REBASE_NO_QUIET)
+		printf(_("First, rewinding head to replay your work on top of "
+			 "it...\n"));
+
+	strbuf_addf(&msg, "%s (start): checkout %s",
+		    options.reflog_action, options.onto_name);
+	ropts.oid = &options.onto->object.oid;
+	ropts.orig_head = &options.orig_head->object.oid,
+	ropts.flags = RESET_HEAD_DETACH | RESET_ORIG_HEAD |
+			RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
+	ropts.head_msg = msg.buf;
+	ropts.default_reflog_action = options.reflog_action;
+	if (reset_head(the_repository, &ropts))
+		die(_("Could not detach HEAD"));
+	strbuf_release(&msg);
+
+	/*
+	 * If the onto is a proper descendant of the tip of the branch, then
+	 * we just fast-forwarded.
+	 */
+	if (oideq(&branch_base, &options.orig_head->object.oid)) {
+		printf(_("Fast-forwarded %s to %s.\n"),
+			branch_name, options.onto_name);
+		move_to_original_branch(&options);
+		ret = finish_rebase(&options);
+		goto cleanup;
+	}
+
+	strbuf_addf(&revisions, "%s..%s",
+		    options.root ? oid_to_hex(&options.onto->object.oid) :
+		    (options.restrict_revision ?
+		     oid_to_hex(&options.restrict_revision->object.oid) :
+		     oid_to_hex(&options.upstream->object.oid)),
+		    oid_to_hex(&options.orig_head->object.oid));
+
+	options.revisions = revisions.buf;
+
+run_rebase:
+	ret = run_specific_rebase(&options);
+
+cleanup:
+	strbuf_release(&buf);
+	strbuf_release(&revisions);
+	free(options.reflog_action);
+	free(options.head_name);
+	free(options.gpg_sign_opt);
+	free(options.cmd);
+	free(options.strategy);
+	strbuf_release(&options.git_format_patch_opt);
+	free(squash_onto_name);
+	return !!ret;
+}