[thirdparty/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] [-q] [<commit>]",
	"git-reset [--mixed] <commit> [--] <paths>...",
	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 is_hard_reset, int quiet)
{
	int i = 0;
	const char *args[6];

	args[i++] = "read-tree";
	if (!quiet)
		args[i++] = "-v";
	args[i++] = "--reset";
	if (is_hard_reset)
		args[i++] = "-u";
	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 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_cache(0) ? 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);
			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)
{
	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);
}

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);
}

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

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_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, options, git_reset_usage,
						PARSE_OPT_KEEP_DASHDASH);
	reflog_action = args_to_str(argv);
	setenv("GIT_REFLOG_ACTION", reflog_action, 0);

	if (i < argc && strcmp(argv[i], "--"))
		rev = 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);

	if (i < argc && !strcmp(argv[i], "--"))
		i++;

	/* 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);
	}
	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 == HARD), 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);
	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);
		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 CR	22	static const char * const git_reset_usage[] = {
	23	"git-reset [--mixed \| --soft \| --hard] [-q] [<commit>]",
	24	"git-reset [--mixed] <commit> [--] <paths>...",
	25	NULL
	26	};
0e5a7faa CR	27
	28	static char args_to_str(const char *argv)
	29	{
	30	char *buf = NULL;
	31	unsigned long len, space = 0, nr = 0;
	32
	33	for (; *argv; argv++) {
	34	len = strlen(*argv);
	35	ALLOC_GROW(buf, nr + 1 + len, space);
	36	if (nr)
	37	buf[nr++] = ' ';
	38	memcpy(buf + nr, *argv, len);
	39	nr += len;
	40	}
	41	ALLOC_GROW(buf, nr + 1, space);
	42	buf[nr] = '\0';
	43
	44	return buf;
	45	}
	46
	47	static inline int is_merge(void)
	48	{
	49	return !access(git_path("MERGE_HEAD"), F_OK);
	50	}
	51
5aa965a0	52	static int reset_index_file(const unsigned char *sha1, int is_hard_reset, int quiet)
0e5a7faa CR	53	{
	54	int i = 0;
	55	const char *args[6];
	56
	57	args[i++] = "read-tree";
5aa965a0 JB	58	if (!quiet)
5aa965a0 JB	59	args[i++] = "-v";
0e5a7faa CR	60	args[i++] = "--reset";
	61	if (is_hard_reset)
	62	args[i++] = "-u";
	63	args[i++] = sha1_to_hex(sha1);
	64	args[i] = NULL;
	65
	66	return run_command_v_opt(args, RUN_GIT_CMD);
	67	}
	68
	69	static void print_new_head_line(struct commit *commit)
	70	{
2efb3b06	71	const char hex, body;
0e5a7faa CR	72
0e5a7faa CR	73	hex = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
2efb3b06	74	printf("HEAD is now at %s", hex);
0e5a7faa CR	75	body = strstr(commit->buffer, "\n\n");
	76	if (body) {
	77	const char *eol;
	78	size_t len;
	79	body += 2;
	80	eol = strchr(body, '\n');
	81	len = eol ? eol - body : strlen(body);
	82	printf(" %.*s\n", (int) len, body);
	83	}
	84	else
	85	printf("\n");
	86	}
	87
620a6cd4	88	static int update_index_refresh(int fd, struct lock_file *index_lock)
0e5a7faa	89	{
620a6cd4	90	int result;
0e5a7faa	91
620a6cd4 JS	92	if (!index_lock) {
	93	index_lock = xcalloc(1, sizeof(struct lock_file));
	94	fd = hold_locked_index(index_lock, 1);
	95	}
0e5a7faa	96
620a6cd4 JS	97	if (read_cache() < 0)
	98	return error("Could not read index");
	99	result = refresh_cache(0) ? 1 : 0;
	100	if (write_cache(fd, active_cache, active_nr) \|\|
620a6cd4 JS	101	commit_locked_index(index_lock))
	102	return error ("Could not refresh index");
	103	return result;
	104	}
2e7a9785	105
0e5a7faa CR	106	static void update_index_from_diff(struct diff_queue_struct *q,
	107	struct diff_options opt, void data)
	108	{
	109	int i;
620a6cd4	110	int *discard_flag = data;
0e5a7faa CR	111
	112	/* do_diff_cache() mangled the index */
	113	discard_cache();
620a6cd4	114	*discard_flag = 1;
0e5a7faa CR	115	read_cache();
	116
	117	for (i = 0; i < q->nr; i++) {
	118	struct diff_filespec *one = q->queue[i]->one;
	119	if (one->mode) {
	120	struct cache_entry *ce;
	121	ce = make_cache_entry(one->mode, one->sha1, one->path,
	122	0, 0);
	123	add_cache_entry(ce, ADD_CACHE_OK_TO_ADD \|
	124	ADD_CACHE_OK_TO_REPLACE);
	125	} else
	126	remove_file_from_cache(one->path);
	127	}
	128	}
	129
	130	static int read_from_tree(const char prefix, const char *argv,
	131	unsigned char *tree_sha1)
	132	{
620a6cd4 JS	133	struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
620a6cd4 JS	134	int index_fd, index_was_discarded = 0;
0e5a7faa CR	135	struct diff_options opt;
	136
	137	memset(&opt, 0, sizeof(opt));
	138	diff_tree_setup_paths(get_pathspec(prefix, (const char **)argv), &opt);
	139	opt.output_format = DIFF_FORMAT_CALLBACK;
	140	opt.format_callback = update_index_from_diff;
620a6cd4	141	opt.format_callback_data = &index_was_discarded;
0e5a7faa	142
620a6cd4 JS	143	index_fd = hold_locked_index(lock, 1);
620a6cd4 JS	144	index_was_discarded = 0;
0e5a7faa CR	145	read_cache();
	146	if (do_diff_cache(tree_sha1, &opt))
	147	return 1;
	148	diffcore_std(&opt);
	149	diff_flush(&opt);
03b69c76	150	diff_tree_release_paths(&opt);
2e7a9785	151
620a6cd4 JS	152	if (!index_was_discarded)
	153	/* The index is still clobbered from do_diff_cache() */
	154	discard_cache();
	155	return update_index_refresh(index_fd, lock);
0e5a7faa CR	156	}
	157
	158	static void prepend_reflog_action(const char action, char buf, size_t size)
	159	{
	160	const char *sep = ": ";
	161	const char *rla = getenv("GIT_REFLOG_ACTION");
	162	if (!rla)
	163	rla = sep = "";
	164	if (snprintf(buf, size, "%s%s%s", rla, sep, action) >= size)
	165	warning("Reflog action message too long: %.*s...", 50, buf);
	166	}
	167
	168	enum reset_type { MIXED, SOFT, HARD, NONE };
538dfe73	169	static const char *reset_type_names[] = { "mixed", "soft", "hard", NULL };
0e5a7faa CR	170
	171	int cmd_reset(int argc, const char *argv, const char prefix)
	172	{
5eee6b28	173	int i = 0, reset_type = NONE, update_ref_status = 0, quiet = 0;
0e5a7faa CR	174	const char *rev = "HEAD";
	175	unsigned char sha1[20], *orig = NULL, sha1_orig[20],
	176	*old_orig = NULL, sha1_old_orig[20];
	177	struct commit *commit;
	178	char *reflog_action, msg[1024];
5eee6b28 CR	179	const struct option options[] = {
	180	OPT_SET_INT(0, "mixed", &reset_type,
	181	"reset HEAD and index", MIXED),
	182	OPT_SET_INT(0, "soft", &reset_type, "reset only HEAD", SOFT),
	183	OPT_SET_INT(0, "hard", &reset_type,
	184	"reset HEAD, index and working tree", HARD),
	185	OPT_BOOLEAN('q', NULL, &quiet,
5aa965a0	186	"disable showing new HEAD in hard reset and progress message"),
5eee6b28 CR	187	OPT_END()
5eee6b28 CR	188	};
0e5a7faa	189
ef90d6d4	190	git_config(git_default_config, NULL);
0e5a7faa	191
5eee6b28 CR	192	argc = parse_options(argc, argv, options, git_reset_usage,
5eee6b28 CR	193	PARSE_OPT_KEEP_DASHDASH);
0e5a7faa CR	194	reflog_action = args_to_str(argv);
	195	setenv("GIT_REFLOG_ACTION", reflog_action, 0);
	196
5eee6b28	197	if (i < argc && strcmp(argv[i], "--"))
0e5a7faa CR	198	rev = argv[i++];
	199
	200	if (get_sha1(rev, sha1))
	201	die("Failed to resolve '%s' as a valid ref.", rev);
	202
	203	commit = lookup_commit_reference(sha1);
	204	if (!commit)
	205	die("Could not parse object '%s'.", rev);
	206	hashcpy(sha1, commit->object.sha1);
	207
	208	if (i < argc && !strcmp(argv[i], "--"))
	209	i++;
0e5a7faa CR	210
	211	/* git reset tree [--] paths... can be used to
	212	* load chosen paths from the tree into the index without
	213	* affecting the working tree nor HEAD. */
	214	if (i < argc) {
	215	if (reset_type == MIXED)
	216	warning("--mixed option is deprecated with paths.");
	217	else if (reset_type != NONE)
	218	die("Cannot do %s reset with paths.",
	219	reset_type_names[reset_type]);
620a6cd4	220	return read_from_tree(prefix, argv + i, sha1);
0e5a7faa CR	221	}
	222	if (reset_type == NONE)
	223	reset_type = MIXED; /* by default */
	224
49b9362f JK	225	if (reset_type == HARD && is_bare_repository())
	226	die("hard reset makes no sense in a bare repository");
	227
0e5a7faa CR	228	/* Soft reset does not touch the index file nor the working tree
	229	* at all, but requires them in a good order. Other resets reset
	230	* the index file to the tree object we are switching to. */
	231	if (reset_type == SOFT) {
94a5728c	232	if (is_merge() \|\| read_cache() < 0 \|\| unmerged_cache())
0e5a7faa CR	233	die("Cannot do a soft reset in the middle of a merge.");
0e5a7faa CR	234	}
5aa965a0	235	else if (reset_index_file(sha1, (reset_type == HARD), quiet))
0e5a7faa CR	236	die("Could not reset index file to revision '%s'.", rev);
	237
	238	/* Any resets update HEAD to the head being switched to,
	239	* saving the previous head in ORIG_HEAD before. */
	240	if (!get_sha1("ORIG_HEAD", sha1_old_orig))
	241	old_orig = sha1_old_orig;
	242	if (!get_sha1("HEAD", sha1_orig)) {
	243	orig = sha1_orig;
	244	prepend_reflog_action("updating ORIG_HEAD", msg, sizeof(msg));
	245	update_ref(msg, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
	246	}
	247	else if (old_orig)
	248	delete_ref("ORIG_HEAD", old_orig);
	249	prepend_reflog_action("updating HEAD", msg, sizeof(msg));
	250	update_ref_status = update_ref(msg, "HEAD", sha1, orig, 0, MSG_ON_ERR);
	251
	252	switch (reset_type) {
	253	case HARD:
521b53e5	254	if (!update_ref_status && !quiet)
0e5a7faa CR	255	print_new_head_line(commit);
	256	break;
	257	case SOFT: /* Nothing else to do. */
	258	break;
	259	case MIXED: /* Report what has not been updated. */
620a6cd4	260	update_index_refresh(0, NULL);
0e5a7faa CR	261	break;
	262	}
	263
c369e7b8	264	remove_branch_state();
0e5a7faa CR	265
	266	free(reflog_action);
	267
	268	return update_ref_status;
	269	}