[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"

/*
 * 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 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_END(),
	};

	if (parse_options(argc, argv, 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 ("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 int merge_recursive(const char *base_sha1,
		const char *head_sha1, const char *head_name,
		const char *next_sha1, const char *next_name)
{
	char buffer[256];
	const char *argv[6];
	int i = 0;

	sprintf(buffer, "GITHEAD_%s", head_sha1);
	setenv(buffer, head_name, 1);
	sprintf(buffer, "GITHEAD_%s", next_sha1);
	setenv(buffer, next_name, 1);

	/*
	 * This three way merge is an interesting one.  We are at
	 * $head, and would want to apply the change between $commit
	 * and $prev on top of us (when reverting), or the change between
	 * $prev and $commit on top of us (when cherry-picking or replaying).
	 */
	argv[i++] = "merge-recursive";
	if (base_sha1)
		argv[i++] = base_sha1;
	argv[i++] = "--";
	argv[i++] = head_sha1;
	argv[i++] = next_sha1;
	argv[i++] = NULL;

	return run_command_v_opt(argv, RUN_COMMAND_NO_STDIN | RUN_GIT_CMD);
}

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 int index_is_dirty(void)
{
	struct rev_info rev;
	init_revisions(&rev, NULL);
	setup_revisions(0, NULL, &rev, "HEAD");
	DIFF_OPT_SET(&rev.diffopt, QUIET);
	DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
	run_diff_index(&rev, 1);
	return !!DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES);
}

static int revert_or_cherry_pick(int argc, const char **argv)
{
	unsigned char head[20];
	struct commit *base, *next, *parent;
	int i;
	char *oneline, *reencoded_message = NULL;
	const char *message, *encoding;
	const char *defmsg = xstrdup(git_path("MERGE_MSG"));

	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 (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 (read_cache() < 0)
			die("could not read the index");
		if (index_is_dirty())
			die ("Dirty index: cannot %s", me);
		discard_cache();
	}

	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));

	/*
	 * "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, 1);

	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));
		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");
		}
	}

	if (merge_recursive(base == NULL ?
				NULL : sha1_to_hex(base->object.sha1),
				sha1_to_hex(head), "HEAD",
				sha1_to_hex(next->object.sha1), oneline) ||
			write_cache_as_tree(head, 0, NULL)) {
		add_to_msg("\nConflicts:\n\n");
		read_cache();
		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();
		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);

	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"
9509af68 JS	15
	16	/*
	17	* This implements the builtins revert and cherry-pick.
	18	*
	19	* Copyright (c) 2007 Johannes E. Schindelin
	20	*
	21	* Based on git-revert.sh, which is
	22	*
	23	* Copyright (c) 2005 Linus Torvalds
	24	* Copyright (c) 2005 Junio C Hamano
	25	*/
	26
f8103794	27	static const char * const revert_usage[] = {
1b1dd23f	28	"git revert [options] <commit-ish>",
f8103794 PH	29	NULL
f8103794 PH	30	};
9509af68	31
f8103794	32	static const char * const cherry_pick_usage[] = {
1b1dd23f	33	"git cherry-pick [options] <commit-ish>",
f8103794 PH	34	NULL
f8103794 PH	35	};
9509af68	36
cfd9c277	37	static int edit, no_replay, no_commit, mainline, signoff;
4175e9e3	38	static enum { REVERT, CHERRY_PICK } action;
9509af68	39	static struct commit *commit;
9509af68 JS	40
	41	static const char *me;
	42
	43	#define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
	44
f8103794	45	static void parse_args(int argc, const char **argv)
9509af68	46	{
f8103794 PH	47	const char * const * usage_str =
f8103794 PH	48	action == REVERT ? revert_usage : cherry_pick_usage;
9509af68 JS	49	unsigned char sha1[20];
9509af68 JS	50	const char *arg;
f8103794 PH	51	int noop;
	52	struct option options[] = {
	53	OPT_BOOLEAN('n', "no-commit", &no_commit, "don't automatically commit"),
	54	OPT_BOOLEAN('e', "edit", &edit, "edit the commit message"),
	55	OPT_BOOLEAN('x', NULL, &no_replay, "append commit name when cherry-picking"),
	56	OPT_BOOLEAN('r', NULL, &noop, "no-op (backward compatibility)"),
cfd9c277	57	OPT_BOOLEAN('s', "signoff", &signoff, "add Signed-off-by:"),
02273fdb	58	OPT_INTEGER('m', "mainline", &mainline, "parent number"),
f8103794 PH	59	OPT_END(),
	60	};
	61
	62	if (parse_options(argc, argv, options, usage_str, 0) != 1)
	63	usage_with_options(usage_str, options);
	64	arg = argv[0];
9509af68	65
9509af68 JS	66	if (get_sha1(arg, sha1))
	67	die ("Cannot find '%s'", arg);
	68	commit = (struct commit *)parse_object(sha1);
	69	if (!commit)
	70	die ("Could not find %s", sha1_to_hex(sha1));
	71	if (commit->object.type == OBJ_TAG) {
	72	commit = (struct commit *)
	73	deref_tag((struct object *)commit, arg, strlen(arg));
9509af68 JS	74	}
	75	if (commit->object.type != OBJ_COMMIT)
	76	die ("'%s' does not point to a commit", arg);
	77	}
	78
	79	static char get_oneline(const char message)
	80	{
	81	char *result;
	82	const char p = message, abbrev, *eol;
	83	int abbrev_len, oneline_len;
	84
	85	if (!p)
	86	die ("Could not read commit message of %s",
	87	sha1_to_hex(commit->object.sha1));
	88	while (p && (p != '\n' \|\| p[1] != '\n'))
	89	p++;
	90
	91	if (*p) {
	92	p += 2;
	93	for (eol = p + 1; eol && eol != '\n'; eol++)
	94	; /* do nothing */
	95	} else
	96	eol = p;
	97	abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
	98	abbrev_len = strlen(abbrev);
	99	oneline_len = eol - p;
	100	result = xmalloc(abbrev_len + 5 + oneline_len);
	101	memcpy(result, abbrev, abbrev_len);
	102	memcpy(result + abbrev_len, "... ", 4);
	103	memcpy(result + abbrev_len + 4, p, oneline_len);
	104	result[abbrev_len + 4 + oneline_len] = '\0';
	105	return result;
	106	}
	107
52fae7de	108	static char get_encoding(const char message)
9509af68 JS	109	{
	110	const char p = message, eol;
	111
	112	if (!p)
	113	die ("Could not read commit message of %s",
	114	sha1_to_hex(commit->object.sha1));
	115	while (p && p != '\n') {
	116	for (eol = p + 1; eol && eol != '\n'; eol++)
	117	; /* do nothing */
	118	if (!prefixcmp(p, "encoding ")) {
	119	char *result = xmalloc(eol - 8 - p);
	120	strlcpy(result, p + 9, eol - 8 - p);
	121	return result;
	122	}
	123	p = eol;
	124	if (*p == '\n')
	125	p++;
	126	}
	127	return NULL;
	128	}
	129
4175e9e3	130	static struct lock_file msg_file;
9509af68 JS	131	static int msg_fd;
	132
	133	static void add_to_msg(const char *string)
	134	{
	135	int len = strlen(string);
	136	if (write_in_full(msg_fd, string, len) < 0)
1dcb3b64	137	die ("Could not write to MERGE_MSG");
9509af68 JS	138	}
	139
	140	static void add_message_to_msg(const char *message)
	141	{
	142	const char *p = message;
	143	while (p && (p != '\n' \|\| p[1] != '\n'))
	144	p++;
	145
	146	if (!*p)
	147	add_to_msg(sha1_to_hex(commit->object.sha1));
	148
	149	p += 2;
	150	add_to_msg(p);
	151	return;
	152	}
	153
	154	static void set_author_ident_env(const char *message)
	155	{
	156	const char *p = message;
	157	if (!p)
	158	die ("Could not read commit message of %s",
	159	sha1_to_hex(commit->object.sha1));
	160	while (p && p != '\n') {
	161	const char *eol;
	162
	163	for (eol = p; eol && eol != '\n'; eol++)
	164	; /* do nothing */
	165	if (!prefixcmp(p, "author ")) {
	166	char line, pend, email, timestamp;
	167
	168	p += 7;
182af834	169	line = xmemdupz(p, eol - p);
9509af68 JS	170	email = strchr(line, '<');
	171	if (!email)
	172	die ("Could not extract author email from %s",
	173	sha1_to_hex(commit->object.sha1));
	174	if (email == line)
	175	pend = line;
	176	else
	177	for (pend = email; pend != line + 1 &&
	178	isspace(pend[-1]); pend--);
	179	; /* do nothing */
	180	*pend = '\0';
	181	email++;
	182	timestamp = strchr(email, '>');
	183	if (!timestamp)
1e5f7add	184	die ("Could not extract author time from %s",
9509af68 JS	185	sha1_to_hex(commit->object.sha1));
	186	*timestamp = '\0';
	187	for (timestamp++; timestamp && isspace(timestamp);
	188	timestamp++)
	189	; /* do nothing */
	190	setenv("GIT_AUTHOR_NAME", line, 1);
	191	setenv("GIT_AUTHOR_EMAIL", email, 1);
	192	setenv("GIT_AUTHOR_DATE", timestamp, 1);
	193	free(line);
	194	return;
	195	}
	196	p = eol;
	197	if (*p == '\n')
	198	p++;
	199	}
	200	die ("No author information found in %s",
	201	sha1_to_hex(commit->object.sha1));
	202	}
	203
	204	static int merge_recursive(const char *base_sha1,
	205	const char head_sha1, const char head_name,
	206	const char next_sha1, const char next_name)
	207	{
	208	char buffer[256];
497bdc88	209	const char *argv[6];
f95ebf74	210	int i = 0;
9509af68 JS	211
	212	sprintf(buffer, "GITHEAD_%s", head_sha1);
	213	setenv(buffer, head_name, 1);
	214	sprintf(buffer, "GITHEAD_%s", next_sha1);
	215	setenv(buffer, next_name, 1);
	216
	217	/*
	218	* This three way merge is an interesting one. We are at
	219	* $head, and would want to apply the change between $commit
	220	* and $prev on top of us (when reverting), or the change between
	221	* $prev and $commit on top of us (when cherry-picking or replaying).
	222	*/
f95ebf74 JS	223	argv[i++] = "merge-recursive";
	224	if (base_sha1)
	225	argv[i++] = base_sha1;
	226	argv[i++] = "--";
	227	argv[i++] = head_sha1;
	228	argv[i++] = next_sha1;
	229	argv[i++] = NULL;
497bdc88 SP	230
497bdc88 SP	231	return run_command_v_opt(argv, RUN_COMMAND_NO_STDIN \| RUN_GIT_CMD);
9509af68 JS	232	}
9509af68 JS	233
804c7174 WC	234	static char help_msg(const unsigned char sha1)
	235	{
	236	static char helpbuf[1024];
	237	char *msg = getenv("GIT_CHERRY_PICK_HELP");
	238
	239	if (msg)
	240	return msg;
	241
	242	strcpy(helpbuf, " After resolving the conflicts,\n"
	243	"mark the corrected paths with 'git add <paths>' "
0d813589	244	"or 'git rm <paths>' and commit the result.");
804c7174 WC	245
	246	if (action == CHERRY_PICK) {
	247	sprintf(helpbuf + strlen(helpbuf),
	248	"\nWhen commiting, use the option "
	249	"'-c %s' to retain authorship and message.",
	250	find_unique_abbrev(sha1, DEFAULT_ABBREV));
	251	}
	252	return helpbuf;
	253	}
	254
0f2d4476 JK	255	static int index_is_dirty(void)
	256	{
	257	struct rev_info rev;
	258	init_revisions(&rev, NULL);
	259	setup_revisions(0, NULL, &rev, "HEAD");
	260	DIFF_OPT_SET(&rev.diffopt, QUIET);
	261	DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
	262	run_diff_index(&rev, 1);
	263	return !!DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES);
	264	}
	265
9509af68 JS	266	static int revert_or_cherry_pick(int argc, const char **argv)
	267	{
	268	unsigned char head[20];
7791ecbc	269	struct commit base, next, *parent;
9509af68	270	int i;
1a8f2741 SP	271	char oneline, reencoded_message = NULL;
1a8f2741 SP	272	const char message, encoding;
abda5227	273	const char *defmsg = xstrdup(git_path("MERGE_MSG"));
9509af68	274
ef90d6d4	275	git_config(git_default_config, NULL);
9509af68 JS	276	me = action == REVERT ? "revert" : "cherry-pick";
9509af68 JS	277	setenv(GIT_REFLOG_ACTION, me, 0);
f8103794	278	parse_args(argc, argv);
9509af68 JS	279
9509af68 JS	280	/* this is copied from the shell script, but it's never triggered... */
f8103794	281	if (action == REVERT && !no_replay)
9509af68 JS	282	die("revert is incompatible with replay");
	283
	284	if (no_commit) {
	285	/*
	286	* We do not intend to commit immediately. We just want to
71aa2b8f JH	287	* merge the differences in, so let's compute the tree
	288	* that represents the "current" state for merge-recursive
	289	* to work on.
9509af68	290	*/
45525bd0	291	if (write_cache_as_tree(head, 0, NULL))
9509af68 JS	292	die ("Your index file is unmerged.");
9509af68 JS	293	} else {
9509af68 JS	294	if (get_sha1("HEAD", head))
9509af68 JS	295	die ("You do not have a valid HEAD");
0f2d4476 JK	296	if (read_cache() < 0)
	297	die("could not read the index");
	298	if (index_is_dirty())
9509af68 JS	299	die ("Dirty index: cannot %s", me);
	300	discard_cache();
	301	}
	302
f95ebf74 JS	303	if (!commit->parents) {
	304	if (action == REVERT)
	305	die ("Cannot revert a root commit");
	306	parent = NULL;
	307	}
	308	else if (commit->parents->next) {
7791ecbc JH	309	/* Reverting or cherry-picking a merge commit */
	310	int cnt;
	311	struct commit_list *p;
	312
	313	if (!mainline)
	314	die("Commit %s is a merge but no -m option was given.",
	315	sha1_to_hex(commit->object.sha1));
	316
	317	for (cnt = 1, p = commit->parents;
	318	cnt != mainline && p;
	319	cnt++)
	320	p = p->next;
	321	if (cnt != mainline \|\| !p)
	322	die("Commit %s does not have parent %d",
	323	sha1_to_hex(commit->object.sha1), mainline);
	324	parent = p->item;
	325	} else if (0 < mainline)
	326	die("Mainline was specified but commit %s is not a merge.",
	327	sha1_to_hex(commit->object.sha1));
	328	else
	329	parent = commit->parents->item;
	330
9509af68 JS	331	if (!(message = commit->buffer))
	332	die ("Cannot get commit message for %s",
	333	sha1_to_hex(commit->object.sha1));
	334
	335	/*
	336	* "commit" is an existing commit. We would want to apply
	337	* the difference it introduces since its first parent "prev"
	338	* on top of the current HEAD if we are cherry-pick. Or the
	339	* reverse of it if we are revert.
	340	*/
	341
abda5227	342	msg_fd = hold_lock_file_for_update(&msg_file, defmsg, 1);
9509af68 JS	343
	344	encoding = get_encoding(message);
	345	if (!encoding)
	346	encoding = "utf-8";
	347	if (!git_commit_encoding)
	348	git_commit_encoding = "utf-8";
	349	if ((reencoded_message = reencode_string(message,
	350	git_commit_encoding, encoding)))
	351	message = reencoded_message;
	352
	353	oneline = get_oneline(message);
	354
	355	if (action == REVERT) {
e43b0105 JS	356	char *oneline_body = strchr(oneline, ' ');
e43b0105 JS	357
9509af68	358	base = commit;
7791ecbc	359	next = parent;
e43b0105 JS	360	add_to_msg("Revert \"");
	361	add_to_msg(oneline_body + 1);
	362	add_to_msg("\"\n\nThis reverts commit ");
9509af68 JS	363	add_to_msg(sha1_to_hex(commit->object.sha1));
	364	add_to_msg(".\n");
	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
f95ebf74 JS	377	if (merge_recursive(base == NULL ?
f95ebf74 JS	378	NULL : sha1_to_hex(base->object.sha1),
9509af68	379	sha1_to_hex(head), "HEAD",
f52463a5	380	sha1_to_hex(next->object.sha1), oneline) \|\|
45525bd0	381	write_cache_as_tree(head, 0, NULL)) {
9509af68 JS	382	add_to_msg("\nConflicts:\n\n");
	383	read_cache();
	384	for (i = 0; i < active_nr;) {
	385	struct cache_entry *ce = active_cache[i++];
	386	if (ce_stage(ce)) {
	387	add_to_msg("\t");
	388	add_to_msg(ce->name);
	389	add_to_msg("\n");
	390	while (i < active_nr && !strcmp(ce->name,
	391	active_cache[i]->name))
	392	i++;
	393	}
	394	}
4ed7cd3a	395	if (commit_lock_file(&msg_file) < 0)
abda5227	396	die ("Error wrapping up %s", defmsg);
804c7174 WC	397	fprintf(stderr, "Automatic %s failed.%s\n",
804c7174 WC	398	me, help_msg(commit->object.sha1));
aa1a0111	399	rerere();
9509af68 JS	400	exit(1);
9509af68 JS	401	}
4ed7cd3a	402	if (commit_lock_file(&msg_file) < 0)
abda5227	403	die ("Error wrapping up %s", defmsg);
9509af68 JS	404	fprintf(stderr, "Finished one %s.\n", me);
	405
	406	/*
	407	*
	408	* If we are cherry-pick, and if the merge did not result in
	409	* hand-editing, we will hit this commit and inherit the original
	410	* author date and name.
	411	* If we are revert, or if our cherry-pick results in a hand merge,
	412	* we had better say that the current user is responsible for that.
	413	*/
	414
	415	if (!no_commit) {
cfd9c277 DM	416	/* 6 is max possible length of our args array including NULL */
	417	const char *args[6];
	418	int i = 0;
	419	args[i++] = "commit";
	420	args[i++] = "-n";
	421	if (signoff)
	422	args[i++] = "-s";
	423	if (!edit) {
	424	args[i++] = "-F";
	425	args[i++] = defmsg;
	426	}
	427	args[i] = NULL;
	428	return execv_git_cmd(args);
9509af68	429	}
8e0f7003	430	free(reencoded_message);
9509af68 JS	431
	432	return 0;
	433	}
	434
	435	int cmd_revert(int argc, const char *argv, const char prefix)
	436	{
	437	if (isatty(0))
	438	edit = 1;
f8103794	439	no_replay = 1;
9509af68 JS	440	action = REVERT;
	441	return revert_or_cherry_pick(argc, argv);
	442	}
	443
	444	int cmd_cherry_pick(int argc, const char *argv, const char prefix)
	445	{
f8103794	446	no_replay = 0;
9509af68 JS	447	action = CHERRY_PICK;
	448	return revert_or_cherry_pick(argc, argv);
	449	}