[git/git.git] / builtin-reset.c

/*
 * "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 "cache.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"

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

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

static char *args_to_str(const char **argv)
{
	char *buf = NULL;
	unsigned long len, space = 0, nr = 0;

	for (; *argv; argv++) {
		len = strlen(*argv);
		ALLOC_GROW(buf, nr + 1 + len, space);
		if (nr)
			buf[nr++] = ' ';
		memcpy(buf + nr, *argv, len);
		nr += len;
	}
	ALLOC_GROW(buf, nr + 1, space);
	buf[nr] = '\0';

	return buf;
}

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 i = 0;
	const char *args[6];

	args[i++] = "read-tree";
	if (!quiet)
		args[i++] = "-v";
	switch (reset_type) {
	case MERGE:
		args[i++] = "-u";
		args[i++] = "-m";
		break;
	case HARD:
		args[i++] = "-u";
		/* fallthrough */
	default:
		args[i++] = "--reset";
	}
	args[i++] = sha1_to_hex(sha1);
	args[i] = NULL;

	return run_command_v_opt(args, RUN_GIT_CMD);
}

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) {
			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 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 prepend_reflog_action(const char *action, char *buf, size_t size)
{
	const char *sep = ": ";
	const char *rla = getenv("GIT_REFLOG_ACTION");
	if (!rla)
		rla = sep = "";
	if (snprintf(buf, size, "%s%s%s", rla, sep, action) >= size)
		warning("Reflog action message too long: %.*s...", 50, buf);
}

int cmd_reset(int argc, const char **argv, const char *prefix)
{
	int i = 0, reset_type = NONE, update_ref_status = 0, quiet = 0;
	const char *rev = "HEAD";
	unsigned char sha1[20], *orig = NULL, sha1_orig[20],
				*old_orig = NULL, sha1_old_orig[20];
	struct commit *commit;
	char *reflog_action, msg[1024];
	const struct option options[] = {
		OPT_SET_INT(0, "mixed", &reset_type,
						"reset HEAD and index", MIXED),
		OPT_SET_INT(0, "soft", &reset_type, "reset only HEAD", SOFT),
		OPT_SET_INT(0, "hard", &reset_type,
				"reset HEAD, index and working tree", HARD),
		OPT_SET_INT(0, "merge", &reset_type,
				"reset HEAD, index and working tree", MERGE),
		OPT_BOOLEAN('q', NULL, &quiet,
				"disable showing new HEAD in hard reset and progress message"),
		OPT_END()
	};

	git_config(git_default_config, NULL);

	argc = parse_options(argc, argv, prefix, options, git_reset_usage,
						PARSE_OPT_KEEP_DASHDASH);
	reflog_action = args_to_str(argv);
	setenv("GIT_REFLOG_ACTION", reflog_action, 0);

	/*
	 * 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(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]);
		}
	}

	if (get_sha1(rev, sha1))
		die("Failed to resolve '%s' as a valid ref.", rev);

	commit = lookup_commit_reference(sha1);
	if (!commit)
		die("Could not parse object '%s'.", rev);
	hashcpy(sha1, commit->object.sha1);

	/* 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 option is deprecated with paths.");
		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 == HARD && is_bare_repository())
		die("hard reset makes no sense in a bare repository");

	/* 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) {
		if (is_merge() || read_cache() < 0 || unmerged_cache())
			die("Cannot do a soft reset in the middle of a merge.");
	}
	else if (reset_index_file(sha1, reset_type, quiet))
		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;
		prepend_reflog_action("updating ORIG_HEAD", msg, sizeof(msg));
		update_ref(msg, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
	}
	else if (old_orig)
		delete_ref("ORIG_HEAD", old_orig, 0);
	prepend_reflog_action("updating HEAD", msg, sizeof(msg));
	update_ref_status = update_ref(msg, "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();

	free(reflog_action);

	return update_ref_status;
}
Commit	Line	Data
0e5a7faa CR	1	/*
	2	* "git reset" builtin command
	3	*
	4	* Copyright (c) 2007 Carlos Rica
	5	*
	6	* Based on git-reset.sh, which is
	7	*
	8	* Copyright (c) 2005, 2006 Linus Torvalds and Junio C Hamano
	9	*/
	10	#include "cache.h"
	11	#include "tag.h"
	12	#include "object.h"
	13	#include "commit.h"
	14	#include "run-command.h"
	15	#include "refs.h"
	16	#include "diff.h"
	17	#include "diffcore.h"
	18	#include "tree.h"
c369e7b8	19	#include "branch.h"
5eee6b28	20	#include "parse-options.h"
0e5a7faa	21
5eee6b28	22	static const char * const git_reset_usage[] = {
9e8eceab	23	"git reset [--mixed \| --soft \| --hard \| --merge] [-q] [<commit>]",
1b1dd23f	24	"git reset [--mixed] <commit> [--] <paths>...",
5eee6b28 CR	25	NULL
5eee6b28 CR	26	};
0e5a7faa	27
9e8eceab LT	28	enum reset_type { MIXED, SOFT, HARD, MERGE, NONE };
	29	static const char *reset_type_names[] = { "mixed", "soft", "hard", "merge", NULL };
	30
0e5a7faa CR	31	static char args_to_str(const char *argv)
	32	{
	33	char *buf = NULL;
	34	unsigned long len, space = 0, nr = 0;
	35
	36	for (; *argv; argv++) {
	37	len = strlen(*argv);
	38	ALLOC_GROW(buf, nr + 1 + len, space);
	39	if (nr)
	40	buf[nr++] = ' ';
	41	memcpy(buf + nr, *argv, len);
	42	nr += len;
	43	}
	44	ALLOC_GROW(buf, nr + 1, space);
	45	buf[nr] = '\0';
	46
	47	return buf;
	48	}
	49
	50	static inline int is_merge(void)
	51	{
	52	return !access(git_path("MERGE_HEAD"), F_OK);
	53	}
	54
9e8eceab	55	static int reset_index_file(const unsigned char *sha1, int reset_type, int quiet)
0e5a7faa CR	56	{
	57	int i = 0;
	58	const char *args[6];
	59
	60	args[i++] = "read-tree";
5aa965a0 JB	61	if (!quiet)
5aa965a0 JB	62	args[i++] = "-v";
9e8eceab LT	63	switch (reset_type) {
9e8eceab LT	64	case MERGE:
0e5a7faa	65	args[i++] = "-u";
9e8eceab LT	66	args[i++] = "-m";
	67	break;
	68	case HARD:
	69	args[i++] = "-u";
	70	/* fallthrough */
	71	default:
	72	args[i++] = "--reset";
	73	}
0e5a7faa CR	74	args[i++] = sha1_to_hex(sha1);
	75	args[i] = NULL;
	76
	77	return run_command_v_opt(args, RUN_GIT_CMD);
	78	}
	79
	80	static void print_new_head_line(struct commit *commit)
	81	{
2efb3b06	82	const char hex, body;
0e5a7faa CR	83
0e5a7faa CR	84	hex = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
2efb3b06	85	printf("HEAD is now at %s", hex);
0e5a7faa CR	86	body = strstr(commit->buffer, "\n\n");
	87	if (body) {
	88	const char *eol;
	89	size_t len;
	90	body += 2;
	91	eol = strchr(body, '\n');
	92	len = eol ? eol - body : strlen(body);
	93	printf(" %.*s\n", (int) len, body);
	94	}
	95	else
	96	printf("\n");
	97	}
	98
b0320eaf	99	static int update_index_refresh(int fd, struct lock_file *index_lock, int flags)
0e5a7faa	100	{
620a6cd4	101	int result;
0e5a7faa	102
620a6cd4 JS	103	if (!index_lock) {
	104	index_lock = xcalloc(1, sizeof(struct lock_file));
	105	fd = hold_locked_index(index_lock, 1);
	106	}
0e5a7faa	107
620a6cd4 JS	108	if (read_cache() < 0)
620a6cd4 JS	109	return error("Could not read index");
b0320eaf	110
3deffc52 MM	111	result = refresh_index(&the_index, (flags), NULL, NULL,
3deffc52 MM	112	"Unstaged changes after reset:") ? 1 : 0;
620a6cd4	113	if (write_cache(fd, active_cache, active_nr) \|\|
620a6cd4 JS	114	commit_locked_index(index_lock))
	115	return error ("Could not refresh index");
	116	return result;
	117	}
2e7a9785	118
0e5a7faa CR	119	static void update_index_from_diff(struct diff_queue_struct *q,
	120	struct diff_options opt, void data)
	121	{
	122	int i;
620a6cd4	123	int *discard_flag = data;
0e5a7faa CR	124
	125	/* do_diff_cache() mangled the index */
	126	discard_cache();
620a6cd4	127	*discard_flag = 1;
0e5a7faa CR	128	read_cache();
	129
	130	for (i = 0; i < q->nr; i++) {
	131	struct diff_filespec *one = q->queue[i]->one;
	132	if (one->mode) {
	133	struct cache_entry *ce;
	134	ce = make_cache_entry(one->mode, one->sha1, one->path,
	135	0, 0);
d09e2cd5 DP	136	if (!ce)
	137	die("make_cache_entry failed for path '%s'",
	138	one->path);
0e5a7faa CR	139	add_cache_entry(ce, ADD_CACHE_OK_TO_ADD \|
	140	ADD_CACHE_OK_TO_REPLACE);
	141	} else
	142	remove_file_from_cache(one->path);
	143	}
	144	}
	145
	146	static int read_from_tree(const char prefix, const char *argv,
b0320eaf	147	unsigned char *tree_sha1, int refresh_flags)
0e5a7faa	148	{
620a6cd4 JS	149	struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
620a6cd4 JS	150	int index_fd, index_was_discarded = 0;
0e5a7faa CR	151	struct diff_options opt;
	152
	153	memset(&opt, 0, sizeof(opt));
	154	diff_tree_setup_paths(get_pathspec(prefix, (const char **)argv), &opt);
	155	opt.output_format = DIFF_FORMAT_CALLBACK;
	156	opt.format_callback = update_index_from_diff;
620a6cd4	157	opt.format_callback_data = &index_was_discarded;
0e5a7faa	158
620a6cd4 JS	159	index_fd = hold_locked_index(lock, 1);
620a6cd4 JS	160	index_was_discarded = 0;
0e5a7faa CR	161	read_cache();
	162	if (do_diff_cache(tree_sha1, &opt))
	163	return 1;
	164	diffcore_std(&opt);
	165	diff_flush(&opt);
03b69c76	166	diff_tree_release_paths(&opt);
2e7a9785	167
620a6cd4 JS	168	if (!index_was_discarded)
	169	/* The index is still clobbered from do_diff_cache() */
	170	discard_cache();
b0320eaf	171	return update_index_refresh(index_fd, lock, refresh_flags);
0e5a7faa CR	172	}
	173
	174	static void prepend_reflog_action(const char action, char buf, size_t size)
	175	{
	176	const char *sep = ": ";
	177	const char *rla = getenv("GIT_REFLOG_ACTION");
	178	if (!rla)
	179	rla = sep = "";
	180	if (snprintf(buf, size, "%s%s%s", rla, sep, action) >= size)
	181	warning("Reflog action message too long: %.*s...", 50, buf);
	182	}
	183
0e5a7faa CR	184	int cmd_reset(int argc, const char *argv, const char prefix)
0e5a7faa CR	185	{
5eee6b28	186	int i = 0, reset_type = NONE, update_ref_status = 0, quiet = 0;
0e5a7faa CR	187	const char *rev = "HEAD";
	188	unsigned char sha1[20], *orig = NULL, sha1_orig[20],
	189	*old_orig = NULL, sha1_old_orig[20];
	190	struct commit *commit;
	191	char *reflog_action, msg[1024];
5eee6b28 CR	192	const struct option options[] = {
	193	OPT_SET_INT(0, "mixed", &reset_type,
	194	"reset HEAD and index", MIXED),
	195	OPT_SET_INT(0, "soft", &reset_type, "reset only HEAD", SOFT),
	196	OPT_SET_INT(0, "hard", &reset_type,
	197	"reset HEAD, index and working tree", HARD),
9e8eceab LT	198	OPT_SET_INT(0, "merge", &reset_type,
9e8eceab LT	199	"reset HEAD, index and working tree", MERGE),
5eee6b28	200	OPT_BOOLEAN('q', NULL, &quiet,
5aa965a0	201	"disable showing new HEAD in hard reset and progress message"),
5eee6b28 CR	202	OPT_END()
5eee6b28 CR	203	};
0e5a7faa	204
ef90d6d4	205	git_config(git_default_config, NULL);
0e5a7faa	206
37782920	207	argc = parse_options(argc, argv, prefix, options, git_reset_usage,
5eee6b28	208	PARSE_OPT_KEEP_DASHDASH);
0e5a7faa CR	209	reflog_action = args_to_str(argv);
	210	setenv("GIT_REFLOG_ACTION", reflog_action, 0);
	211
dfc8f39e JH	212	/*
	213	* Possible arguments are:
	214	*
	215	* git reset [-opts] <rev> <paths>...
	216	* git reset [-opts] <rev> -- <paths>...
	217	* git reset [-opts] -- <paths>...
	218	* git reset [-opts] <paths>...
	219	*
	220	* At this point, argv[i] points immediately after [-opts].
	221	*/
	222
	223	if (i < argc) {
	224	if (!strcmp(argv[i], "--")) {
	225	i++; /* reset to HEAD, possibly with paths */
	226	} else if (i + 1 < argc && !strcmp(argv[i+1], "--")) {
	227	rev = argv[i];
	228	i += 2;
	229	}
	230	/*
	231	* Otherwise, argv[i] could be either <rev> or <paths> and
3ea3c215	232	* has to be unambiguous.
dfc8f39e JH	233	*/
	234	else if (!get_sha1(argv[i], sha1)) {
	235	/*
	236	* Ok, argv[i] looks like a rev; it should not
	237	* be a filename.
	238	*/
	239	verify_non_filename(prefix, argv[i]);
	240	rev = argv[i++];
	241	} else {
	242	/* Otherwise we treat this as a filename */
	243	verify_filename(prefix, argv[i]);
	244	}
	245	}
0e5a7faa CR	246
	247	if (get_sha1(rev, sha1))
	248	die("Failed to resolve '%s' as a valid ref.", rev);
	249
	250	commit = lookup_commit_reference(sha1);
	251	if (!commit)
	252	die("Could not parse object '%s'.", rev);
	253	hashcpy(sha1, commit->object.sha1);
	254
0e5a7faa CR	255	/* git reset tree [--] paths... can be used to
	256	* load chosen paths from the tree into the index without
	257	* affecting the working tree nor HEAD. */
	258	if (i < argc) {
	259	if (reset_type == MIXED)
	260	warning("--mixed option is deprecated with paths.");
	261	else if (reset_type != NONE)
	262	die("Cannot do %s reset with paths.",
	263	reset_type_names[reset_type]);
b0320eaf	264	return read_from_tree(prefix, argv + i, sha1,
43673fdd	265	quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN);
0e5a7faa CR	266	}
	267	if (reset_type == NONE)
	268	reset_type = MIXED; /* by default */
	269
49b9362f JK	270	if (reset_type == HARD && is_bare_repository())
	271	die("hard reset makes no sense in a bare repository");
	272
0e5a7faa CR	273	/* Soft reset does not touch the index file nor the working tree
	274	* at all, but requires them in a good order. Other resets reset
	275	* the index file to the tree object we are switching to. */
	276	if (reset_type == SOFT) {
94a5728c	277	if (is_merge() \|\| read_cache() < 0 \|\| unmerged_cache())
0e5a7faa CR	278	die("Cannot do a soft reset in the middle of a merge.");
0e5a7faa CR	279	}
9e8eceab	280	else if (reset_index_file(sha1, reset_type, quiet))
0e5a7faa CR	281	die("Could not reset index file to revision '%s'.", rev);
	282
	283	/* Any resets update HEAD to the head being switched to,
	284	* saving the previous head in ORIG_HEAD before. */
	285	if (!get_sha1("ORIG_HEAD", sha1_old_orig))
	286	old_orig = sha1_old_orig;
	287	if (!get_sha1("HEAD", sha1_orig)) {
	288	orig = sha1_orig;
	289	prepend_reflog_action("updating ORIG_HEAD", msg, sizeof(msg));
	290	update_ref(msg, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
	291	}
	292	else if (old_orig)
eca35a25	293	delete_ref("ORIG_HEAD", old_orig, 0);
0e5a7faa CR	294	prepend_reflog_action("updating HEAD", msg, sizeof(msg));
	295	update_ref_status = update_ref(msg, "HEAD", sha1, orig, 0, MSG_ON_ERR);
	296
	297	switch (reset_type) {
	298	case HARD:
521b53e5	299	if (!update_ref_status && !quiet)
0e5a7faa CR	300	print_new_head_line(commit);
	301	break;
	302	case SOFT: /* Nothing else to do. */
	303	break;
	304	case MIXED: /* Report what has not been updated. */
b0320eaf	305	update_index_refresh(0, NULL,
43673fdd	306	quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN);
0e5a7faa CR	307	break;
	308	}
	309
c369e7b8	310	remove_branch_state();
0e5a7faa CR	311
	312	free(reflog_action);
	313
	314	return update_ref_status;
	315	}