builtin/reset.c - git - Git at Google

 /*
  * "git reset" builtin command
  *
  * Copyright (c) 2007 Carlos Rica
  *
  * Based on git-reset.sh, which is
  *
  * Copyright (c) 2005, 2006 Linus Torvalds and Junio C Hamano
  */
 #include "builtin.h"
 #include "tag.h"
 #include "object.h"
 #include "commit.h"
 #include "run-command.h"
 #include "refs.h"
 #include "diff.h"
 #include "diffcore.h"
 #include "tree.h"
 #include "branch.h"
 #include "parse-options.h"
 #include "unpack-trees.h"
 #include "cache-tree.h"

 static const char * const git_reset_usage[] = {
 	N_("git reset [--mixed | --soft | --hard | --merge | --keep] [-q] [<commit>]"),
 	N_("git reset [-q] <commit> [--] <paths>..."),
 	N_("git reset --patch [<commit>] [--] [<paths>...]"),
 	NULL
 };

 enum reset_type { MIXED, SOFT, HARD, MERGE, KEEP, NONE };
 static const char *reset_type_names[] = {
 	N_("mixed"), N_("soft"), N_("hard"), N_("merge"), N_("keep"), NULL
 };

 static inline int is_merge(void)
 {
 	return !access(git_path("MERGE_HEAD"), F_OK);
 }

 static int reset_index_file(const unsigned char *sha1, int reset_type, int quiet)
 {
 	int nr = 1;
 	int newfd;
 	struct tree_desc desc[2];
 	struct tree *tree;
 	struct unpack_trees_options opts;
 	struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));

 	memset(&opts, 0, sizeof(opts));
 	opts.head_idx = 1;
 	opts.src_index = &the_index;
 	opts.dst_index = &the_index;
 	opts.fn = oneway_merge;
 	opts.merge = 1;
 	if (!quiet)
 		opts.verbose_update = 1;
 	switch (reset_type) {
 	case KEEP:
 	case MERGE:
 		opts.update = 1;
 		break;
 	case HARD:
 		opts.update = 1;
 		/* fallthrough */
 	default:
 		opts.reset = 1;
 	}

 	newfd = hold_locked_index(lock, 1);

 	read_cache_unmerged();

 	if (reset_type == KEEP) {
 		unsigned char head_sha1[20];
 		if (get_sha1("HEAD", head_sha1))
 			return error(_("You do not have a valid HEAD."));
 		if (!fill_tree_descriptor(desc, head_sha1))
 			return error(_("Failed to find tree of HEAD."));
 		nr++;
 		opts.fn = twoway_merge;
 	}

 	if (!fill_tree_descriptor(desc + nr - 1, sha1))
 		return error(_("Failed to find tree of %s."), sha1_to_hex(sha1));
 	if (unpack_trees(nr, desc, &opts))
 		return -1;

 	if (reset_type == MIXED || reset_type == HARD) {
 		tree = parse_tree_indirect(sha1);
 		prime_cache_tree(&active_cache_tree, tree);
 	}

 	if (write_cache(newfd, active_cache, active_nr) ||
 	    commit_locked_index(lock))
 		return error(_("Could not write new index file."));

 	return 0;
 }

 static void print_new_head_line(struct commit *commit)
 {
 	const char *hex, *body;

 	hex = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
 	printf(_("HEAD is now at %s"), hex);
 	body = strstr(commit->buffer, "\n\n");
 	if (body) {
 		const char *eol;
 		size_t len;
 		body += 2;
 		eol = strchr(body, '\n');
 		len = eol ? eol - body : strlen(body);
 		printf(" %.*s\n", (int) len, body);
 	}
 	else
 		printf("\n");
 }

 static int update_index_refresh(int fd, struct lock_file *index_lock, int flags)
 {
 	int result;

 	if (!index_lock) {
 		index_lock = xcalloc(1, sizeof(struct lock_file));
 		fd = hold_locked_index(index_lock, 1);
 	}

 	if (read_cache() < 0)
 		return error(_("Could not read index"));

 	result = refresh_index(&the_index, (flags), NULL, NULL,
 			       _("Unstaged changes after reset:")) ? 1 : 0;
 	if (write_cache(fd, active_cache, active_nr) ||
 			commit_locked_index(index_lock))
 		return error ("Could not refresh index");
 	return result;
 }

 static void update_index_from_diff(struct diff_queue_struct *q,
 		struct diff_options *opt, void *data)
 {
 	int i;
 	int *discard_flag = data;

 	/* do_diff_cache() mangled the index */
 	discard_cache();
 	*discard_flag = 1;
 	read_cache();

 	for (i = 0; i < q->nr; i++) {
 		struct diff_filespec *one = q->queue[i]->one;
 		if (one->mode && !is_null_sha1(one->sha1)) {
 			struct cache_entry *ce;
 			ce = make_cache_entry(one->mode, one->sha1, one->path,
 				0, 0);
 			if (!ce)
 				die(_("make_cache_entry failed for path '%s'"),
 				    one->path);
 			add_cache_entry(ce, ADD_CACHE_OK_TO_ADD |
 				ADD_CACHE_OK_TO_REPLACE);
 		} else
 			remove_file_from_cache(one->path);
 	}
 }

 static int interactive_reset(const char *revision, const char **argv,
 			     const char *prefix)
 {
 	const char **pathspec = NULL;

 	if (*argv)
 		pathspec = get_pathspec(prefix, argv);

 	return run_add_interactive(revision, "--patch=reset", pathspec);
 }

 static int read_from_tree(const char *prefix, const char **argv,
 		unsigned char *tree_sha1, int refresh_flags)
 {
 	struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
 	int index_fd, index_was_discarded = 0;
 	struct diff_options opt;

 	memset(&opt, 0, sizeof(opt));
 	diff_tree_setup_paths(get_pathspec(prefix, (const char **)argv), &opt);
 	opt.output_format = DIFF_FORMAT_CALLBACK;
 	opt.format_callback = update_index_from_diff;
 	opt.format_callback_data = &index_was_discarded;

 	index_fd = hold_locked_index(lock, 1);
 	index_was_discarded = 0;
 	read_cache();
 	if (do_diff_cache(tree_sha1, &opt))
 		return 1;
 	diffcore_std(&opt);
 	diff_flush(&opt);
 	diff_tree_release_paths(&opt);

 	if (!index_was_discarded)
 		/* The index is still clobbered from do_diff_cache() */
 		discard_cache();
 	return update_index_refresh(index_fd, lock, refresh_flags);
 }

 static void set_reflog_message(struct strbuf *sb, const char *action,
 			       const char *rev)
 {
 	const char *rla = getenv("GIT_REFLOG_ACTION");

 	strbuf_reset(sb);
 	if (rla)
 		strbuf_addf(sb, "%s: %s", rla, action);
 	else if (rev)
 		strbuf_addf(sb, "reset: moving to %s", rev);
 	else
 		strbuf_addf(sb, "reset: %s", action);
 }

 static void die_if_unmerged_cache(int reset_type)
 {
 	if (is_merge() || read_cache() < 0 || unmerged_cache())
 		die(_("Cannot do a %s reset in the middle of a merge."),
 		    _(reset_type_names[reset_type]));

 }

 int cmd_reset(int argc, const char **argv, const char *prefix)
 {
 	int i = 0, reset_type = NONE, update_ref_status = 0, quiet = 0;
 	int patch_mode = 0;
 	const char *rev = "HEAD";
 	unsigned char sha1[20], *orig = NULL, sha1_orig[20],
 				*old_orig = NULL, sha1_old_orig[20];
 	struct commit *commit;
 	struct strbuf msg = STRBUF_INIT;
 	const struct option options[] = {
 		OPT__QUIET(&quiet, N_("be quiet, only report errors")),
 		OPT_SET_INT(0, "mixed", &reset_type,
 						N_("reset HEAD and index"), MIXED),
 		OPT_SET_INT(0, "soft", &reset_type, N_("reset only HEAD"), SOFT),
 		OPT_SET_INT(0, "hard", &reset_type,
 				N_("reset HEAD, index and working tree"), HARD),
 		OPT_SET_INT(0, "merge", &reset_type,
 				N_("reset HEAD, index and working tree"), MERGE),
 		OPT_SET_INT(0, "keep", &reset_type,
 				N_("reset HEAD but keep local changes"), KEEP),
 		OPT_BOOLEAN('p', "patch", &patch_mode, N_("select hunks interactively")),
 		OPT_END()
 	};

 	git_config(git_default_config, NULL);

 	argc = parse_options(argc, argv, prefix, options, git_reset_usage,
 						PARSE_OPT_KEEP_DASHDASH);

 	/*
 	 * Possible arguments are:
 	 *
 	 * git reset [-opts] <rev> <paths>...
 	 * git reset [-opts] <rev> -- <paths>...
 	 * git reset [-opts] -- <paths>...
 	 * git reset [-opts] <paths>...
 	 *
 	 * At this point, argv[i] points immediately after [-opts].
 	 */

 	if (i < argc) {
 		if (!strcmp(argv[i], "--")) {
 			i++; /* reset to HEAD, possibly with paths */
 		} else if (i + 1 < argc && !strcmp(argv[i+1], "--")) {
 			rev = argv[i];
 			i += 2;
 		}
 		/*
 		 * Otherwise, argv[i] could be either <rev> or <paths> and
 		 * has to be unambiguous.
 		 */
 		else if (!get_sha1_committish(argv[i], sha1)) {
 			/*
 			 * Ok, argv[i] looks like a rev; it should not
 			 * be a filename.
 			 */
 			verify_non_filename(prefix, argv[i]);
 			rev = argv[i++];
 		} else {
 			/* Otherwise we treat this as a filename */
 			verify_filename(prefix, argv[i], 1);
 		}
 	}

 	if (get_sha1_committish(rev, sha1))
 		die(_("Failed to resolve '%s' as a valid ref."), rev);

 	/*
 	 * NOTE: As "git reset $treeish -- $path" should be usable on
 	 * any tree-ish, this is not strictly correct. We are not
 	 * moving the HEAD to any commit; we are merely resetting the
 	 * entries in the index to that of a treeish.
 	 */
 	commit = lookup_commit_reference(sha1);
 	if (!commit)
 		die(_("Could not parse object '%s'."), rev);
 	hashcpy(sha1, commit->object.sha1);

 	if (patch_mode) {
 		if (reset_type != NONE)
 			die(_("--patch is incompatible with --{hard,mixed,soft}"));
 		return interactive_reset(rev, argv + i, prefix);
 	}

 	/* git reset tree [--] paths... can be used to
 	 * load chosen paths from the tree into the index without
 	 * affecting the working tree nor HEAD. */
 	if (i < argc) {
 		if (reset_type == MIXED)
 			warning(_("--mixed with paths is deprecated; use 'git reset -- <paths>' instead."));
 		else if (reset_type != NONE)
 			die(_("Cannot do %s reset with paths."),
 					_(reset_type_names[reset_type]));
 		return read_from_tree(prefix, argv + i, sha1,
 				quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN);
 	}
 	if (reset_type == NONE)
 		reset_type = MIXED; /* by default */

 	if (reset_type != SOFT && reset_type != MIXED)
 		setup_work_tree();

 	if (reset_type == MIXED && is_bare_repository())
 		die(_("%s reset is not allowed in a bare repository"),
 		    _(reset_type_names[reset_type]));

 	/* Soft reset does not touch the index file nor the working tree
 	 * at all, but requires them in a good order.  Other resets reset
 	 * the index file to the tree object we are switching to. */
 	if (reset_type == SOFT)
 		die_if_unmerged_cache(reset_type);
 	else {
 		int err;
 		if (reset_type == KEEP)
 			die_if_unmerged_cache(reset_type);
 		err = reset_index_file(sha1, reset_type, quiet);
 		if (reset_type == KEEP)
 			err = err || reset_index_file(sha1, MIXED, quiet);
 		if (err)
 			die(_("Could not reset index file to revision '%s'."), rev);
 	}

 	/* Any resets update HEAD to the head being switched to,
 	 * saving the previous head in ORIG_HEAD before. */
 	if (!get_sha1("ORIG_HEAD", sha1_old_orig))
 		old_orig = sha1_old_orig;
 	if (!get_sha1("HEAD", sha1_orig)) {
 		orig = sha1_orig;
 		set_reflog_message(&msg, "updating ORIG_HEAD", NULL);
 		update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
 	}
 	else if (old_orig)
 		delete_ref("ORIG_HEAD", old_orig, 0);
 	set_reflog_message(&msg, "updating HEAD", rev);
 	update_ref_status = update_ref(msg.buf, "HEAD", sha1, orig, 0, MSG_ON_ERR);

 	switch (reset_type) {
 	case HARD:
 		if (!update_ref_status && !quiet)
 			print_new_head_line(commit);
 		break;
 	case SOFT: /* Nothing else to do. */
 		break;
 	case MIXED: /* Report what has not been updated. */
 		update_index_refresh(0, NULL,
 				quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN);
 		break;
 	}

 	remove_branch_state();

 	strbuf_release(&msg);

 	return update_ref_status;
 }
	/*
	* "git reset" builtin command
	*
	* Copyright (c) 2007 Carlos Rica
	*
	* Based on git-reset.sh, which is
	*
	* Copyright (c) 2005, 2006 Linus Torvalds and Junio C Hamano
	*/
	#include "builtin.h"
	#include "tag.h"
	#include "object.h"
	#include "commit.h"
	#include "run-command.h"
	#include "refs.h"
	#include "diff.h"
	#include "diffcore.h"
	#include "tree.h"
	#include "branch.h"
	#include "parse-options.h"
	#include "unpack-trees.h"
	#include "cache-tree.h"

	static const char * const git_reset_usage[] = {
	N_("git reset [--mixed \| --soft \| --hard \| --merge \| --keep] [-q] [<commit>]"),
	N_("git reset [-q] <commit> [--] <paths>..."),
	N_("git reset --patch [<commit>] [--] [<paths>...]"),
	NULL
	};

	enum reset_type { MIXED, SOFT, HARD, MERGE, KEEP, NONE };
	static const char *reset_type_names[] = {
	N_("mixed"), N_("soft"), N_("hard"), N_("merge"), N_("keep"), NULL
	};

	static inline int is_merge(void)
	{
	return !access(git_path("MERGE_HEAD"), F_OK);
	}

	static int reset_index_file(const unsigned char *sha1, int reset_type, int quiet)
	{
	int nr = 1;
	int newfd;
	struct tree_desc desc[2];
	struct tree *tree;
	struct unpack_trees_options opts;
	struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));

	memset(&opts, 0, sizeof(opts));
	opts.head_idx = 1;
	opts.src_index = &the_index;
	opts.dst_index = &the_index;
	opts.fn = oneway_merge;
	opts.merge = 1;
	if (!quiet)
	opts.verbose_update = 1;
	switch (reset_type) {
	case KEEP:
	case MERGE:
	opts.update = 1;
	break;
	case HARD:
	opts.update = 1;
	/* fallthrough */
	default:
	opts.reset = 1;
	}

	newfd = hold_locked_index(lock, 1);

	read_cache_unmerged();

	if (reset_type == KEEP) {
	unsigned char head_sha1[20];
	if (get_sha1("HEAD", head_sha1))
	return error(_("You do not have a valid HEAD."));
	if (!fill_tree_descriptor(desc, head_sha1))
	return error(_("Failed to find tree of HEAD."));
	nr++;
	opts.fn = twoway_merge;
	}

	if (!fill_tree_descriptor(desc + nr - 1, sha1))
	return error(_("Failed to find tree of %s."), sha1_to_hex(sha1));
	if (unpack_trees(nr, desc, &opts))
	return -1;

	if (reset_type == MIXED \|\| reset_type == HARD) {
	tree = parse_tree_indirect(sha1);
	prime_cache_tree(&active_cache_tree, tree);
	}

	if (write_cache(newfd, active_cache, active_nr) \|\|
	commit_locked_index(lock))
	return error(_("Could not write new index file."));

	return 0;
	}

	static void print_new_head_line(struct commit *commit)
	{
	const char hex, body;

	hex = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
	printf(_("HEAD is now at %s"), hex);
	body = strstr(commit->buffer, "\n\n");
	if (body) {
	const char *eol;
	size_t len;
	body += 2;
	eol = strchr(body, '\n');
	len = eol ? eol - body : strlen(body);
	printf(" %.*s\n", (int) len, body);
	}
	else
	printf("\n");
	}

	static int update_index_refresh(int fd, struct lock_file *index_lock, int flags)
	{
	int result;

	if (!index_lock) {
	index_lock = xcalloc(1, sizeof(struct lock_file));
	fd = hold_locked_index(index_lock, 1);
	}

	if (read_cache() < 0)
	return error(_("Could not read index"));

	result = refresh_index(&the_index, (flags), NULL, NULL,
	_("Unstaged changes after reset:")) ? 1 : 0;
	if (write_cache(fd, active_cache, active_nr) \|\|
	commit_locked_index(index_lock))
	return error ("Could not refresh index");
	return result;
	}

	static void update_index_from_diff(struct diff_queue_struct *q,
	struct diff_options opt, void data)
	{
	int i;
	int *discard_flag = data;

	/* do_diff_cache() mangled the index */
	discard_cache();
	*discard_flag = 1;
	read_cache();

	for (i = 0; i < q->nr; i++) {
	struct diff_filespec *one = q->queue[i]->one;
	if (one->mode && !is_null_sha1(one->sha1)) {
	struct cache_entry *ce;
	ce = make_cache_entry(one->mode, one->sha1, one->path,
	0, 0);
	if (!ce)
	die(_("make_cache_entry failed for path '%s'"),
	one->path);
	add_cache_entry(ce, ADD_CACHE_OK_TO_ADD \|
	ADD_CACHE_OK_TO_REPLACE);
	} else
	remove_file_from_cache(one->path);
	}
	}

	static int interactive_reset(const char revision, const char *argv,
	const char *prefix)
	{
	const char **pathspec = NULL;

	if (*argv)
	pathspec = get_pathspec(prefix, argv);

	return run_add_interactive(revision, "--patch=reset", pathspec);
	}

	static int read_from_tree(const char prefix, const char *argv,
	unsigned char *tree_sha1, int refresh_flags)
	{
	struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
	int index_fd, index_was_discarded = 0;
	struct diff_options opt;

	memset(&opt, 0, sizeof(opt));
	diff_tree_setup_paths(get_pathspec(prefix, (const char **)argv), &opt);
	opt.output_format = DIFF_FORMAT_CALLBACK;
	opt.format_callback = update_index_from_diff;
	opt.format_callback_data = &index_was_discarded;

	index_fd = hold_locked_index(lock, 1);
	index_was_discarded = 0;
	read_cache();
	if (do_diff_cache(tree_sha1, &opt))
	return 1;
	diffcore_std(&opt);
	diff_flush(&opt);
	diff_tree_release_paths(&opt);

	if (!index_was_discarded)
	/* The index is still clobbered from do_diff_cache() */
	discard_cache();
	return update_index_refresh(index_fd, lock, refresh_flags);
	}

	static void set_reflog_message(struct strbuf sb, const char action,
	const char *rev)
	{
	const char *rla = getenv("GIT_REFLOG_ACTION");

	strbuf_reset(sb);
	if (rla)
	strbuf_addf(sb, "%s: %s", rla, action);
	else if (rev)
	strbuf_addf(sb, "reset: moving to %s", rev);
	else
	strbuf_addf(sb, "reset: %s", action);
	}

	static void die_if_unmerged_cache(int reset_type)
	{
	if (is_merge() \|\| read_cache() < 0 \|\| unmerged_cache())
	die(_("Cannot do a %s reset in the middle of a merge."),
	_(reset_type_names[reset_type]));

	}

	int cmd_reset(int argc, const char *argv, const char prefix)
	{
	int i = 0, reset_type = NONE, update_ref_status = 0, quiet = 0;
	int patch_mode = 0;
	const char *rev = "HEAD";
	unsigned char sha1[20], *orig = NULL, sha1_orig[20],
	*old_orig = NULL, sha1_old_orig[20];
	struct commit *commit;
	struct strbuf msg = STRBUF_INIT;
	const struct option options[] = {
	OPT__QUIET(&quiet, N_("be quiet, only report errors")),
	OPT_SET_INT(0, "mixed", &reset_type,
	N_("reset HEAD and index"), MIXED),
	OPT_SET_INT(0, "soft", &reset_type, N_("reset only HEAD"), SOFT),
	OPT_SET_INT(0, "hard", &reset_type,
	N_("reset HEAD, index and working tree"), HARD),
	OPT_SET_INT(0, "merge", &reset_type,
	N_("reset HEAD, index and working tree"), MERGE),
	OPT_SET_INT(0, "keep", &reset_type,
	N_("reset HEAD but keep local changes"), KEEP),
	OPT_BOOLEAN('p', "patch", &patch_mode, N_("select hunks interactively")),
	OPT_END()
	};

	git_config(git_default_config, NULL);

	argc = parse_options(argc, argv, prefix, options, git_reset_usage,
	PARSE_OPT_KEEP_DASHDASH);

	/*
	* Possible arguments are:
	*
	* git reset [-opts] <rev> <paths>...
	* git reset [-opts] <rev> -- <paths>...
	* git reset [-opts] -- <paths>...
	* git reset [-opts] <paths>...
	*
	* At this point, argv[i] points immediately after [-opts].
	*/

	if (i < argc) {
	if (!strcmp(argv[i], "--")) {
	i++; /* reset to HEAD, possibly with paths */
	} else if (i + 1 < argc && !strcmp(argv[i+1], "--")) {
	rev = argv[i];
	i += 2;
	}
	/*
	* Otherwise, argv[i] could be either <rev> or <paths> and
	* has to be unambiguous.
	*/
	else if (!get_sha1_committish(argv[i], sha1)) {
	/*
	* Ok, argv[i] looks like a rev; it should not
	* be a filename.
	*/
	verify_non_filename(prefix, argv[i]);
	rev = argv[i++];
	} else {
	/* Otherwise we treat this as a filename */
	verify_filename(prefix, argv[i], 1);
	}
	}

	if (get_sha1_committish(rev, sha1))
	die(_("Failed to resolve '%s' as a valid ref."), rev);

	/*
	* NOTE: As "git reset $treeish -- $path" should be usable on
	* any tree-ish, this is not strictly correct. We are not
	* moving the HEAD to any commit; we are merely resetting the
	* entries in the index to that of a treeish.
	*/
	commit = lookup_commit_reference(sha1);
	if (!commit)
	die(_("Could not parse object '%s'."), rev);
	hashcpy(sha1, commit->object.sha1);

	if (patch_mode) {
	if (reset_type != NONE)
	die(_("--patch is incompatible with --{hard,mixed,soft}"));
	return interactive_reset(rev, argv + i, prefix);
	}

	/* git reset tree [--] paths... can be used to
	* load chosen paths from the tree into the index without
	* affecting the working tree nor HEAD. */
	if (i < argc) {
	if (reset_type == MIXED)
	warning(_("--mixed with paths is deprecated; use 'git reset -- <paths>' instead."));
	else if (reset_type != NONE)
	die(_("Cannot do %s reset with paths."),
	_(reset_type_names[reset_type]));
	return read_from_tree(prefix, argv + i, sha1,
	quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN);
	}
	if (reset_type == NONE)
	reset_type = MIXED; /* by default */

	if (reset_type != SOFT && reset_type != MIXED)
	setup_work_tree();

	if (reset_type == MIXED && is_bare_repository())
	die(_("%s reset is not allowed in a bare repository"),
	_(reset_type_names[reset_type]));

	/* Soft reset does not touch the index file nor the working tree
	* at all, but requires them in a good order. Other resets reset
	* the index file to the tree object we are switching to. */
	if (reset_type == SOFT)
	die_if_unmerged_cache(reset_type);
	else {
	int err;
	if (reset_type == KEEP)
	die_if_unmerged_cache(reset_type);
	err = reset_index_file(sha1, reset_type, quiet);
	if (reset_type == KEEP)
	err = err \|\| reset_index_file(sha1, MIXED, quiet);
	if (err)
	die(_("Could not reset index file to revision '%s'."), rev);
	}

	/* Any resets update HEAD to the head being switched to,
	* saving the previous head in ORIG_HEAD before. */
	if (!get_sha1("ORIG_HEAD", sha1_old_orig))
	old_orig = sha1_old_orig;
	if (!get_sha1("HEAD", sha1_orig)) {
	orig = sha1_orig;
	set_reflog_message(&msg, "updating ORIG_HEAD", NULL);
	update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
	}
	else if (old_orig)
	delete_ref("ORIG_HEAD", old_orig, 0);
	set_reflog_message(&msg, "updating HEAD", rev);
	update_ref_status = update_ref(msg.buf, "HEAD", sha1, orig, 0, MSG_ON_ERR);

	switch (reset_type) {
	case HARD:
	if (!update_ref_status && !quiet)
	print_new_head_line(commit);
	break;
	case SOFT: /* Nothing else to do. */
	break;
	case MIXED: /* Report what has not been updated. */
	update_index_refresh(0, NULL,
	quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN);
	break;
	}

	remove_branch_state();

	strbuf_release(&msg);

	return update_ref_status;
	}