[thirdparty/git.git] / builtin-revert.c

#include "cache.h"
#include "builtin.h"
#include "object.h"
#include "commit.h"
#include "tag.h"
#include "wt-status.h"
#include "run-command.h"
#include "exec_cmd.h"
#include "utf8.h"
#include "parse-options.h"
#include "cache-tree.h"
#include "diff.h"
#include "revision.h"
#include "rerere.h"
#include "merge-recursive.h"

/*
 * This implements the builtins revert and cherry-pick.
 *
 * Copyright (c) 2007 Johannes E. Schindelin
 *
 * Based on git-revert.sh, which is
 *
 * Copyright (c) 2005 Linus Torvalds
 * Copyright (c) 2005 Junio C Hamano
 */

static const char * const revert_usage[] = {
	"git revert [options] <commit-ish>",
	NULL
};

static const char * const cherry_pick_usage[] = {
	"git cherry-pick [options] <commit-ish>",
	NULL
};

static int edit, no_replay, no_commit, mainline, signoff;
static enum { REVERT, CHERRY_PICK } action;
static struct commit *commit;
static int allow_rerere_auto;

static const char *me;

#define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"

static void parse_args(int argc, const char **argv)
{
	const char * const * usage_str =
		action == REVERT ?  revert_usage : cherry_pick_usage;
	unsigned char sha1[20];
	const char *arg;
	int noop;
	struct option options[] = {
		OPT_BOOLEAN('n', "no-commit", &no_commit, "don't automatically commit"),
		OPT_BOOLEAN('e', "edit", &edit, "edit the commit message"),
		OPT_BOOLEAN('x', NULL, &no_replay, "append commit name when cherry-picking"),
		OPT_BOOLEAN('r', NULL, &noop, "no-op (backward compatibility)"),
		OPT_BOOLEAN('s', "signoff", &signoff, "add Signed-off-by:"),
		OPT_INTEGER('m', "mainline", &mainline, "parent number"),
		OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
		OPT_END(),
	};

	if (parse_options(argc, argv, NULL, options, usage_str, 0) != 1)
		usage_with_options(usage_str, options);
	arg = argv[0];

	if (get_sha1(arg, sha1))
		die ("Cannot find '%s'", arg);
	commit = (struct commit *)parse_object(sha1);
	if (!commit)
		die ("Could not find %s", sha1_to_hex(sha1));
	if (commit->object.type == OBJ_TAG) {
		commit = (struct commit *)
			deref_tag((struct object *)commit, arg, strlen(arg));
	}
	if (commit->object.type != OBJ_COMMIT)
		die ("'%s' does not point to a commit", arg);
}

static char *get_oneline(const char *message)
{
	char *result;
	const char *p = message, *abbrev, *eol;
	int abbrev_len, oneline_len;

	if (!p)
		die ("Could not read commit message of %s",
				sha1_to_hex(commit->object.sha1));
	while (*p && (*p != '\n' || p[1] != '\n'))
		p++;

	if (*p) {
		p += 2;
		for (eol = p + 1; *eol && *eol != '\n'; eol++)
			; /* do nothing */
	} else
		eol = p;
	abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
	abbrev_len = strlen(abbrev);
	oneline_len = eol - p;
	result = xmalloc(abbrev_len + 5 + oneline_len);
	memcpy(result, abbrev, abbrev_len);
	memcpy(result + abbrev_len, "... ", 4);
	memcpy(result + abbrev_len + 4, p, oneline_len);
	result[abbrev_len + 4 + oneline_len] = '\0';
	return result;
}

static char *get_encoding(const char *message)
{
	const char *p = message, *eol;

	if (!p)
		die ("Could not read commit message of %s",
				sha1_to_hex(commit->object.sha1));
	while (*p && *p != '\n') {
		for (eol = p + 1; *eol && *eol != '\n'; eol++)
			; /* do nothing */
		if (!prefixcmp(p, "encoding ")) {
			char *result = xmalloc(eol - 8 - p);
			strlcpy(result, p + 9, eol - 8 - p);
			return result;
		}
		p = eol;
		if (*p == '\n')
			p++;
	}
	return NULL;
}

static struct lock_file msg_file;
static int msg_fd;

static void add_to_msg(const char *string)
{
	int len = strlen(string);
	if (write_in_full(msg_fd, string, len) < 0)
		die_errno ("Could not write to MERGE_MSG");
}

static void add_message_to_msg(const char *message)
{
	const char *p = message;
	while (*p && (*p != '\n' || p[1] != '\n'))
		p++;

	if (!*p)
		add_to_msg(sha1_to_hex(commit->object.sha1));

	p += 2;
	add_to_msg(p);
	return;
}

static void set_author_ident_env(const char *message)
{
	const char *p = message;
	if (!p)
		die ("Could not read commit message of %s",
				sha1_to_hex(commit->object.sha1));
	while (*p && *p != '\n') {
		const char *eol;

		for (eol = p; *eol && *eol != '\n'; eol++)
			; /* do nothing */
		if (!prefixcmp(p, "author ")) {
			char *line, *pend, *email, *timestamp;

			p += 7;
			line = xmemdupz(p, eol - p);
			email = strchr(line, '<');
			if (!email)
				die ("Could not extract author email from %s",
					sha1_to_hex(commit->object.sha1));
			if (email == line)
				pend = line;
			else
				for (pend = email; pend != line + 1 &&
						isspace(pend[-1]); pend--);
					; /* do nothing */
			*pend = '\0';
			email++;
			timestamp = strchr(email, '>');
			if (!timestamp)
				die ("Could not extract author time from %s",
					sha1_to_hex(commit->object.sha1));
			*timestamp = '\0';
			for (timestamp++; *timestamp && isspace(*timestamp);
					timestamp++)
				; /* do nothing */
			setenv("GIT_AUTHOR_NAME", line, 1);
			setenv("GIT_AUTHOR_EMAIL", email, 1);
			setenv("GIT_AUTHOR_DATE", timestamp, 1);
			free(line);
			return;
		}
		p = eol;
		if (*p == '\n')
			p++;
	}
	die ("No author information found in %s",
			sha1_to_hex(commit->object.sha1));
}

static char *help_msg(const unsigned char *sha1)
{
	static char helpbuf[1024];
	char *msg = getenv("GIT_CHERRY_PICK_HELP");

	if (msg)
		return msg;

	strcpy(helpbuf, "  After resolving the conflicts,\n"
	       "mark the corrected paths with 'git add <paths>' "
	       "or 'git rm <paths>' and commit the result.");

	if (action == CHERRY_PICK) {
		sprintf(helpbuf + strlen(helpbuf),
			"\nWhen commiting, use the option "
			"'-c %s' to retain authorship and message.",
			find_unique_abbrev(sha1, DEFAULT_ABBREV));
	}
	return helpbuf;
}

static struct tree *empty_tree(void)
{
	struct tree *tree = xcalloc(1, sizeof(struct tree));

	tree->object.parsed = 1;
	tree->object.type = OBJ_TREE;
	pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
	return tree;
}

static NORETURN void die_dirty_index(const char *me)
{
	if (read_cache_unmerged()) {
		die_resolve_conflict(me);
	} else {
		if (advice_commit_before_merge)
			die("Your local changes would be overwritten by %s.\n"
			    "Please, commit your changes or stash them to proceed.", me);
		else
			die("Your local changes would be overwritten by %s.\n", me);
	}
}

static int revert_or_cherry_pick(int argc, const char **argv)
{
	unsigned char head[20];
	struct commit *base, *next, *parent;
	int i, index_fd, clean;
	char *oneline, *reencoded_message = NULL;
	const char *message, *encoding;
	char *defmsg = git_pathdup("MERGE_MSG");
	struct merge_options o;
	struct tree *result, *next_tree, *base_tree, *head_tree;
	static struct lock_file index_lock;

	git_config(git_default_config, NULL);
	me = action == REVERT ? "revert" : "cherry-pick";
	setenv(GIT_REFLOG_ACTION, me, 0);
	parse_args(argc, argv);

	/* this is copied from the shell script, but it's never triggered... */
	if (action == REVERT && !no_replay)
		die("revert is incompatible with replay");

	if (read_cache() < 0)
		die("git %s: failed to read the index", me);
	if (no_commit) {
		/*
		 * We do not intend to commit immediately.  We just want to
		 * merge the differences in, so let's compute the tree
		 * that represents the "current" state for merge-recursive
		 * to work on.
		 */
		if (write_cache_as_tree(head, 0, NULL))
			die ("Your index file is unmerged.");
	} else {
		if (get_sha1("HEAD", head))
			die ("You do not have a valid HEAD");
		if (index_differs_from("HEAD", 0))
			die_dirty_index(me);
	}
	discard_cache();

	index_fd = hold_locked_index(&index_lock, 1);

	if (!commit->parents) {
		if (action == REVERT)
			die ("Cannot revert a root commit");
		parent = NULL;
	}
	else if (commit->parents->next) {
		/* Reverting or cherry-picking a merge commit */
		int cnt;
		struct commit_list *p;

		if (!mainline)
			die("Commit %s is a merge but no -m option was given.",
			    sha1_to_hex(commit->object.sha1));

		for (cnt = 1, p = commit->parents;
		     cnt != mainline && p;
		     cnt++)
			p = p->next;
		if (cnt != mainline || !p)
			die("Commit %s does not have parent %d",
			    sha1_to_hex(commit->object.sha1), mainline);
		parent = p->item;
	} else if (0 < mainline)
		die("Mainline was specified but commit %s is not a merge.",
		    sha1_to_hex(commit->object.sha1));
	else
		parent = commit->parents->item;

	if (!(message = commit->buffer))
		die ("Cannot get commit message for %s",
				sha1_to_hex(commit->object.sha1));

	if (parent && parse_commit(parent) < 0)
		die("%s: cannot parse parent commit %s",
		    me, sha1_to_hex(parent->object.sha1));

	/*
	 * "commit" is an existing commit.  We would want to apply
	 * the difference it introduces since its first parent "prev"
	 * on top of the current HEAD if we are cherry-pick.  Or the
	 * reverse of it if we are revert.
	 */

	msg_fd = hold_lock_file_for_update(&msg_file, defmsg,
					   LOCK_DIE_ON_ERROR);

	encoding = get_encoding(message);
	if (!encoding)
		encoding = "UTF-8";
	if (!git_commit_encoding)
		git_commit_encoding = "UTF-8";
	if ((reencoded_message = reencode_string(message,
					git_commit_encoding, encoding)))
		message = reencoded_message;

	oneline = get_oneline(message);

	if (action == REVERT) {
		char *oneline_body = strchr(oneline, ' ');

		base = commit;
		next = parent;
		add_to_msg("Revert \"");
		add_to_msg(oneline_body + 1);
		add_to_msg("\"\n\nThis reverts commit ");
		add_to_msg(sha1_to_hex(commit->object.sha1));

		if (commit->parents->next) {
			add_to_msg(", reversing\nchanges made to ");
			add_to_msg(sha1_to_hex(parent->object.sha1));
		}
		add_to_msg(".\n");
	} else {
		base = parent;
		next = commit;
		set_author_ident_env(message);
		add_message_to_msg(message);
		if (no_replay) {
			add_to_msg("(cherry picked from commit ");
			add_to_msg(sha1_to_hex(commit->object.sha1));
			add_to_msg(")\n");
		}
	}

	read_cache();
	init_merge_options(&o);
	o.branch1 = "HEAD";
	o.branch2 = oneline;

	head_tree = parse_tree_indirect(head);
	next_tree = next ? next->tree : empty_tree();
	base_tree = base ? base->tree : empty_tree();

	clean = merge_trees(&o,
			    head_tree,
			    next_tree, base_tree, &result);

	if (active_cache_changed &&
	    (write_cache(index_fd, active_cache, active_nr) ||
	     commit_locked_index(&index_lock)))
		die("%s: Unable to write new index file", me);
	rollback_lock_file(&index_lock);

	if (!clean) {
		add_to_msg("\nConflicts:\n\n");
		for (i = 0; i < active_nr;) {
			struct cache_entry *ce = active_cache[i++];
			if (ce_stage(ce)) {
				add_to_msg("\t");
				add_to_msg(ce->name);
				add_to_msg("\n");
				while (i < active_nr && !strcmp(ce->name,
						active_cache[i]->name))
					i++;
			}
		}
		if (commit_lock_file(&msg_file) < 0)
			die ("Error wrapping up %s", defmsg);
		fprintf(stderr, "Automatic %s failed.%s\n",
			me, help_msg(commit->object.sha1));
		rerere(allow_rerere_auto);
		exit(1);
	}
	if (commit_lock_file(&msg_file) < 0)
		die ("Error wrapping up %s", defmsg);
	fprintf(stderr, "Finished one %s.\n", me);

	/*
	 *
	 * If we are cherry-pick, and if the merge did not result in
	 * hand-editing, we will hit this commit and inherit the original
	 * author date and name.
	 * If we are revert, or if our cherry-pick results in a hand merge,
	 * we had better say that the current user is responsible for that.
	 */

	if (!no_commit) {
		/* 6 is max possible length of our args array including NULL */
		const char *args[6];
		int i = 0;
		args[i++] = "commit";
		args[i++] = "-n";
		if (signoff)
			args[i++] = "-s";
		if (!edit) {
			args[i++] = "-F";
			args[i++] = defmsg;
		}
		args[i] = NULL;
		return execv_git_cmd(args);
	}
	free(reencoded_message);
	free(defmsg);

	return 0;
}

int cmd_revert(int argc, const char **argv, const char *prefix)
{
	if (isatty(0))
		edit = 1;
	no_replay = 1;
	action = REVERT;
	return revert_or_cherry_pick(argc, argv);
}

int cmd_cherry_pick(int argc, const char **argv, const char *prefix)
{
	no_replay = 0;
	action = CHERRY_PICK;
	return revert_or_cherry_pick(argc, argv);
}
Commit	Line	Data
9509af68 JS	1	#include "cache.h"
	2	#include "builtin.h"
	3	#include "object.h"
	4	#include "commit.h"
	5	#include "tag.h"
	6	#include "wt-status.h"
	7	#include "run-command.h"
	8	#include "exec_cmd.h"
	9	#include "utf8.h"
f8103794	10	#include "parse-options.h"
45525bd0	11	#include "cache-tree.h"
0f2d4476 JK	12	#include "diff.h"
0f2d4476 JK	13	#include "revision.h"
aa1a0111	14	#include "rerere.h"
6eb1b437	15	#include "merge-recursive.h"
9509af68 JS	16
	17	/*
	18	* This implements the builtins revert and cherry-pick.
	19	*
	20	* Copyright (c) 2007 Johannes E. Schindelin
	21	*
	22	* Based on git-revert.sh, which is
	23	*
	24	* Copyright (c) 2005 Linus Torvalds
	25	* Copyright (c) 2005 Junio C Hamano
	26	*/
	27
f8103794	28	static const char * const revert_usage[] = {
1b1dd23f	29	"git revert [options] <commit-ish>",
f8103794 PH	30	NULL
f8103794 PH	31	};
9509af68	32
f8103794	33	static const char * const cherry_pick_usage[] = {
1b1dd23f	34	"git cherry-pick [options] <commit-ish>",
f8103794 PH	35	NULL
f8103794 PH	36	};
9509af68	37
cfd9c277	38	static int edit, no_replay, no_commit, mainline, signoff;
4175e9e3	39	static enum { REVERT, CHERRY_PICK } action;
9509af68	40	static struct commit *commit;
cb6020bb	41	static int allow_rerere_auto;
9509af68 JS	42
	43	static const char *me;
	44
	45	#define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
	46
f8103794	47	static void parse_args(int argc, const char **argv)
9509af68	48	{
f8103794 PH	49	const char * const * usage_str =
f8103794 PH	50	action == REVERT ? revert_usage : cherry_pick_usage;
9509af68 JS	51	unsigned char sha1[20];
9509af68 JS	52	const char *arg;
f8103794 PH	53	int noop;
	54	struct option options[] = {
	55	OPT_BOOLEAN('n', "no-commit", &no_commit, "don't automatically commit"),
	56	OPT_BOOLEAN('e', "edit", &edit, "edit the commit message"),
	57	OPT_BOOLEAN('x', NULL, &no_replay, "append commit name when cherry-picking"),
	58	OPT_BOOLEAN('r', NULL, &noop, "no-op (backward compatibility)"),
cfd9c277	59	OPT_BOOLEAN('s', "signoff", &signoff, "add Signed-off-by:"),
02273fdb	60	OPT_INTEGER('m', "mainline", &mainline, "parent number"),
cb6020bb	61	OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
f8103794 PH	62	OPT_END(),
	63	};
	64
37782920	65	if (parse_options(argc, argv, NULL, options, usage_str, 0) != 1)
f8103794 PH	66	usage_with_options(usage_str, options);
f8103794 PH	67	arg = argv[0];
9509af68	68
9509af68 JS	69	if (get_sha1(arg, sha1))
	70	die ("Cannot find '%s'", arg);
	71	commit = (struct commit *)parse_object(sha1);
	72	if (!commit)
	73	die ("Could not find %s", sha1_to_hex(sha1));
	74	if (commit->object.type == OBJ_TAG) {
	75	commit = (struct commit *)
	76	deref_tag((struct object *)commit, arg, strlen(arg));
9509af68 JS	77	}
	78	if (commit->object.type != OBJ_COMMIT)
	79	die ("'%s' does not point to a commit", arg);
	80	}
	81
	82	static char get_oneline(const char message)
	83	{
	84	char *result;
	85	const char p = message, abbrev, *eol;
	86	int abbrev_len, oneline_len;
	87
	88	if (!p)
	89	die ("Could not read commit message of %s",
	90	sha1_to_hex(commit->object.sha1));
	91	while (p && (p != '\n' \|\| p[1] != '\n'))
	92	p++;
	93
	94	if (*p) {
	95	p += 2;
	96	for (eol = p + 1; eol && eol != '\n'; eol++)
	97	; /* do nothing */
	98	} else
	99	eol = p;
	100	abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
	101	abbrev_len = strlen(abbrev);
	102	oneline_len = eol - p;
	103	result = xmalloc(abbrev_len + 5 + oneline_len);
	104	memcpy(result, abbrev, abbrev_len);
	105	memcpy(result + abbrev_len, "... ", 4);
	106	memcpy(result + abbrev_len + 4, p, oneline_len);
	107	result[abbrev_len + 4 + oneline_len] = '\0';
	108	return result;
	109	}
	110
52fae7de	111	static char get_encoding(const char message)
9509af68 JS	112	{
	113	const char p = message, eol;
	114
	115	if (!p)
	116	die ("Could not read commit message of %s",
	117	sha1_to_hex(commit->object.sha1));
	118	while (p && p != '\n') {
	119	for (eol = p + 1; eol && eol != '\n'; eol++)
	120	; /* do nothing */
	121	if (!prefixcmp(p, "encoding ")) {
	122	char *result = xmalloc(eol - 8 - p);
	123	strlcpy(result, p + 9, eol - 8 - p);
	124	return result;
	125	}
	126	p = eol;
	127	if (*p == '\n')
	128	p++;
	129	}
	130	return NULL;
	131	}
	132
4175e9e3	133	static struct lock_file msg_file;
9509af68 JS	134	static int msg_fd;
	135
	136	static void add_to_msg(const char *string)
	137	{
	138	int len = strlen(string);
	139	if (write_in_full(msg_fd, string, len) < 0)
0721c314	140	die_errno ("Could not write to MERGE_MSG");
9509af68 JS	141	}
	142
	143	static void add_message_to_msg(const char *message)
	144	{
	145	const char *p = message;
	146	while (p && (p != '\n' \|\| p[1] != '\n'))
	147	p++;
	148
	149	if (!*p)
	150	add_to_msg(sha1_to_hex(commit->object.sha1));
	151
	152	p += 2;
	153	add_to_msg(p);
	154	return;
	155	}
	156
	157	static void set_author_ident_env(const char *message)
	158	{
	159	const char *p = message;
	160	if (!p)
	161	die ("Could not read commit message of %s",
	162	sha1_to_hex(commit->object.sha1));
	163	while (p && p != '\n') {
	164	const char *eol;
	165
	166	for (eol = p; eol && eol != '\n'; eol++)
	167	; /* do nothing */
	168	if (!prefixcmp(p, "author ")) {
	169	char line, pend, email, timestamp;
	170
	171	p += 7;
182af834	172	line = xmemdupz(p, eol - p);
9509af68 JS	173	email = strchr(line, '<');
	174	if (!email)
	175	die ("Could not extract author email from %s",
	176	sha1_to_hex(commit->object.sha1));
	177	if (email == line)
	178	pend = line;
	179	else
	180	for (pend = email; pend != line + 1 &&
	181	isspace(pend[-1]); pend--);
	182	; /* do nothing */
	183	*pend = '\0';
	184	email++;
	185	timestamp = strchr(email, '>');
	186	if (!timestamp)
1e5f7add	187	die ("Could not extract author time from %s",
9509af68 JS	188	sha1_to_hex(commit->object.sha1));
	189	*timestamp = '\0';
	190	for (timestamp++; timestamp && isspace(timestamp);
	191	timestamp++)
	192	; /* do nothing */
	193	setenv("GIT_AUTHOR_NAME", line, 1);
	194	setenv("GIT_AUTHOR_EMAIL", email, 1);
	195	setenv("GIT_AUTHOR_DATE", timestamp, 1);
	196	free(line);
	197	return;
	198	}
	199	p = eol;
	200	if (*p == '\n')
	201	p++;
	202	}
	203	die ("No author information found in %s",
	204	sha1_to_hex(commit->object.sha1));
	205	}
	206
804c7174 WC	207	static char help_msg(const unsigned char sha1)
	208	{
	209	static char helpbuf[1024];
	210	char *msg = getenv("GIT_CHERRY_PICK_HELP");
	211
	212	if (msg)
	213	return msg;
	214
	215	strcpy(helpbuf, " After resolving the conflicts,\n"
	216	"mark the corrected paths with 'git add <paths>' "
0d813589	217	"or 'git rm <paths>' and commit the result.");
804c7174 WC	218
	219	if (action == CHERRY_PICK) {
	220	sprintf(helpbuf + strlen(helpbuf),
	221	"\nWhen commiting, use the option "
	222	"'-c %s' to retain authorship and message.",
	223	find_unique_abbrev(sha1, DEFAULT_ABBREV));
	224	}
	225	return helpbuf;
	226	}
	227
6eb1b437 MV	228	static struct tree *empty_tree(void)
	229	{
	230	struct tree *tree = xcalloc(1, sizeof(struct tree));
	231
	232	tree->object.parsed = 1;
	233	tree->object.type = OBJ_TREE;
	234	pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
	235	return tree;
	236	}
	237
d38a30df MM	238	static NORETURN void die_dirty_index(const char *me)
	239	{
	240	if (read_cache_unmerged()) {
	241	die_resolve_conflict(me);
	242	} else {
	243	if (advice_commit_before_merge)
	244	die("Your local changes would be overwritten by %s.\n"
	245	"Please, commit your changes or stash them to proceed.", me);
	246	else
	247	die("Your local changes would be overwritten by %s.\n", me);
	248	}
	249	}
	250
9509af68 JS	251	static int revert_or_cherry_pick(int argc, const char **argv)
	252	{
	253	unsigned char head[20];
7791ecbc	254	struct commit base, next, *parent;
6eb1b437	255	int i, index_fd, clean;
1a8f2741 SP	256	char oneline, reencoded_message = NULL;
1a8f2741 SP	257	const char message, encoding;
a1a846a1	258	char *defmsg = git_pathdup("MERGE_MSG");
6eb1b437 MV	259	struct merge_options o;
	260	struct tree result, next_tree, base_tree, head_tree;
	261	static struct lock_file index_lock;
9509af68	262
ef90d6d4	263	git_config(git_default_config, NULL);
9509af68 JS	264	me = action == REVERT ? "revert" : "cherry-pick";
9509af68 JS	265	setenv(GIT_REFLOG_ACTION, me, 0);
f8103794	266	parse_args(argc, argv);
9509af68 JS	267
9509af68 JS	268	/* this is copied from the shell script, but it's never triggered... */
f8103794	269	if (action == REVERT && !no_replay)
9509af68 JS	270	die("revert is incompatible with replay");
9509af68 JS	271
6eb1b437 MV	272	if (read_cache() < 0)
6eb1b437 MV	273	die("git %s: failed to read the index", me);
9509af68 JS	274	if (no_commit) {
	275	/*
	276	* We do not intend to commit immediately. We just want to
71aa2b8f JH	277	* merge the differences in, so let's compute the tree
	278	* that represents the "current" state for merge-recursive
	279	* to work on.
9509af68	280	*/
45525bd0	281	if (write_cache_as_tree(head, 0, NULL))
9509af68 JS	282	die ("Your index file is unmerged.");
9509af68 JS	283	} else {
9509af68 JS	284	if (get_sha1("HEAD", head))
9509af68 JS	285	die ("You do not have a valid HEAD");
75f3ff2e	286	if (index_differs_from("HEAD", 0))
d38a30df	287	die_dirty_index(me);
9509af68	288	}
6eb1b437 MV	289	discard_cache();
	290
	291	index_fd = hold_locked_index(&index_lock, 1);
9509af68	292
f95ebf74 JS	293	if (!commit->parents) {
	294	if (action == REVERT)
	295	die ("Cannot revert a root commit");
	296	parent = NULL;
	297	}
	298	else if (commit->parents->next) {
7791ecbc JH	299	/* Reverting or cherry-picking a merge commit */
	300	int cnt;
	301	struct commit_list *p;
	302
	303	if (!mainline)
	304	die("Commit %s is a merge but no -m option was given.",
	305	sha1_to_hex(commit->object.sha1));
	306
	307	for (cnt = 1, p = commit->parents;
	308	cnt != mainline && p;
	309	cnt++)
	310	p = p->next;
	311	if (cnt != mainline \|\| !p)
	312	die("Commit %s does not have parent %d",
	313	sha1_to_hex(commit->object.sha1), mainline);
	314	parent = p->item;
	315	} else if (0 < mainline)
	316	die("Mainline was specified but commit %s is not a merge.",
	317	sha1_to_hex(commit->object.sha1));
	318	else
	319	parent = commit->parents->item;
	320
9509af68 JS	321	if (!(message = commit->buffer))
	322	die ("Cannot get commit message for %s",
	323	sha1_to_hex(commit->object.sha1));
	324
6eb1b437 MV	325	if (parent && parse_commit(parent) < 0)
	326	die("%s: cannot parse parent commit %s",
	327	me, sha1_to_hex(parent->object.sha1));
	328
9509af68 JS	329	/*
	330	* "commit" is an existing commit. We would want to apply
	331	* the difference it introduces since its first parent "prev"
	332	* on top of the current HEAD if we are cherry-pick. Or the
	333	* reverse of it if we are revert.
	334	*/
	335
acd3b9ec JH	336	msg_fd = hold_lock_file_for_update(&msg_file, defmsg,
acd3b9ec JH	337	LOCK_DIE_ON_ERROR);
9509af68 JS	338
	339	encoding = get_encoding(message);
	340	if (!encoding)
330db18c	341	encoding = "UTF-8";
9509af68	342	if (!git_commit_encoding)
330db18c	343	git_commit_encoding = "UTF-8";
9509af68 JS	344	if ((reencoded_message = reencode_string(message,
	345	git_commit_encoding, encoding)))
	346	message = reencoded_message;
	347
	348	oneline = get_oneline(message);
	349
	350	if (action == REVERT) {
e43b0105 JS	351	char *oneline_body = strchr(oneline, ' ');
e43b0105 JS	352
9509af68	353	base = commit;
7791ecbc	354	next = parent;
e43b0105 JS	355	add_to_msg("Revert \"");
	356	add_to_msg(oneline_body + 1);
	357	add_to_msg("\"\n\nThis reverts commit ");
9509af68	358	add_to_msg(sha1_to_hex(commit->object.sha1));
d5be89d8 RR	359
	360	if (commit->parents->next) {
	361	add_to_msg(", reversing\nchanges made to ");
	362	add_to_msg(sha1_to_hex(parent->object.sha1));
	363	}
9509af68 JS	364	add_to_msg(".\n");
9509af68 JS	365	} else {
7791ecbc	366	base = parent;
9509af68 JS	367	next = commit;
	368	set_author_ident_env(message);
	369	add_message_to_msg(message);
f8103794	370	if (no_replay) {
0e624044	371	add_to_msg("(cherry picked from commit ");
9509af68 JS	372	add_to_msg(sha1_to_hex(commit->object.sha1));
	373	add_to_msg(")\n");
	374	}
	375	}
9509af68	376
6eb1b437 MV	377	read_cache();
	378	init_merge_options(&o);
	379	o.branch1 = "HEAD";
	380	o.branch2 = oneline;
	381
	382	head_tree = parse_tree_indirect(head);
	383	next_tree = next ? next->tree : empty_tree();
	384	base_tree = base ? base->tree : empty_tree();
	385
	386	clean = merge_trees(&o,
	387	head_tree,
	388	next_tree, base_tree, &result);
	389
	390	if (active_cache_changed &&
	391	(write_cache(index_fd, active_cache, active_nr) \|\|
	392	commit_locked_index(&index_lock)))
	393	die("%s: Unable to write new index file", me);
0d66e959	394	rollback_lock_file(&index_lock);
6eb1b437 MV	395
6eb1b437 MV	396	if (!clean) {
9509af68	397	add_to_msg("\nConflicts:\n\n");
9509af68 JS	398	for (i = 0; i < active_nr;) {
	399	struct cache_entry *ce = active_cache[i++];
	400	if (ce_stage(ce)) {
	401	add_to_msg("\t");
	402	add_to_msg(ce->name);
	403	add_to_msg("\n");
	404	while (i < active_nr && !strcmp(ce->name,
	405	active_cache[i]->name))
	406	i++;
	407	}
	408	}
4ed7cd3a	409	if (commit_lock_file(&msg_file) < 0)
abda5227	410	die ("Error wrapping up %s", defmsg);
804c7174 WC	411	fprintf(stderr, "Automatic %s failed.%s\n",
804c7174 WC	412	me, help_msg(commit->object.sha1));
cb6020bb	413	rerere(allow_rerere_auto);
9509af68 JS	414	exit(1);
9509af68 JS	415	}
4ed7cd3a	416	if (commit_lock_file(&msg_file) < 0)
abda5227	417	die ("Error wrapping up %s", defmsg);
9509af68 JS	418	fprintf(stderr, "Finished one %s.\n", me);
	419
	420	/*
	421	*
	422	* If we are cherry-pick, and if the merge did not result in
	423	* hand-editing, we will hit this commit and inherit the original
	424	* author date and name.
	425	* If we are revert, or if our cherry-pick results in a hand merge,
	426	* we had better say that the current user is responsible for that.
	427	*/
	428
	429	if (!no_commit) {
cfd9c277 DM	430	/* 6 is max possible length of our args array including NULL */
	431	const char *args[6];
	432	int i = 0;
	433	args[i++] = "commit";
	434	args[i++] = "-n";
	435	if (signoff)
	436	args[i++] = "-s";
	437	if (!edit) {
	438	args[i++] = "-F";
	439	args[i++] = defmsg;
	440	}
	441	args[i] = NULL;
	442	return execv_git_cmd(args);
9509af68	443	}
8e0f7003	444	free(reencoded_message);
d258b258	445	free(defmsg);
9509af68 JS	446
	447	return 0;
	448	}
	449
	450	int cmd_revert(int argc, const char *argv, const char prefix)
	451	{
	452	if (isatty(0))
	453	edit = 1;
f8103794	454	no_replay = 1;
9509af68 JS	455	action = REVERT;
	456	return revert_or_cherry_pick(argc, argv);
	457	}
	458
	459	int cmd_cherry_pick(int argc, const char *argv, const char prefix)
	460	{
f8103794	461	no_replay = 0;
9509af68 JS	462	action = CHERRY_PICK;
	463	return revert_or_cherry_pick(argc, argv);
	464	}