[thirdparty/git.git] / builtin / update-ref.c

#include "cache.h"
#include "refs.h"
#include "builtin.h"
#include "parse-options.h"
#include "quote.h"
#include "argv-array.h"

static const char * const git_update_ref_usage[] = {
	N_("git update-ref [options] -d <refname> [<oldval>]"),
	N_("git update-ref [options]    <refname> <newval> [<oldval>]"),
	N_("git update-ref [options] --stdin [-z]"),
	NULL
};

static struct ref_transaction *transaction;

static char line_termination = '\n';
static int update_flags;

/*
 * Parse one whitespace- or NUL-terminated, possibly C-quoted argument
 * and append the result to arg.  Return a pointer to the terminator.
 * Die if there is an error in how the argument is C-quoted.  This
 * function is only used if not -z.
 */
static const char *parse_arg(const char *next, struct strbuf *arg)
{
	if (*next == '"') {
		const char *orig = next;

		if (unquote_c_style(arg, next, &next))
			die("badly quoted argument: %s", orig);
		if (*next && !isspace(*next))
			die("unexpected character after quoted argument: %s", orig);
	} else {
		while (*next && !isspace(*next))
			strbuf_addch(arg, *next++);
	}

	return next;
}

/*
 * Parse the reference name immediately after "command SP".  If not
 * -z, then handle C-quoting.  Return a pointer to a newly allocated
 * string containing the name of the reference, or NULL if there was
 * an error.  Update *next to point at the character that terminates
 * the argument.  Die if C-quoting is malformed or the reference name
 * is invalid.
 */
static char *parse_refname(struct strbuf *input, const char **next)
{
	struct strbuf ref = STRBUF_INIT;

	if (line_termination) {
		/* Without -z, use the next argument */
		*next = parse_arg(*next, &ref);
	} else {
		/* With -z, use everything up to the next NUL */
		strbuf_addstr(&ref, *next);
		*next += ref.len;
	}

	if (!ref.len) {
		strbuf_release(&ref);
		return NULL;
	}

	if (check_refname_format(ref.buf, REFNAME_ALLOW_ONELEVEL))
		die("invalid ref format: %s", ref.buf);

	return strbuf_detach(&ref, NULL);
}

/*
 * The value being parsed is <oldvalue> (as opposed to <newvalue>; the
 * difference affects which error messages are generated):
 */
#define PARSE_SHA1_OLD 0x01

/*
 * For backwards compatibility, accept an empty string for update's
 * <newvalue> in binary mode to be equivalent to specifying zeros.
 */
#define PARSE_SHA1_ALLOW_EMPTY 0x02

/*
 * Parse an argument separator followed by the next argument, if any.
 * If there is an argument, convert it to a SHA-1, write it to sha1,
 * set *next to point at the character terminating the argument, and
 * return 0.  If there is no argument at all (not even the empty
 * string), return 1 and leave *next unchanged.  If the value is
 * provided but cannot be converted to a SHA-1, die.  flags can
 * include PARSE_SHA1_OLD and/or PARSE_SHA1_ALLOW_EMPTY.
 */
static int parse_next_sha1(struct strbuf *input, const char **next,
			   unsigned char *sha1,
			   const char *command, const char *refname,
			   int flags)
{
	struct strbuf arg = STRBUF_INIT;
	int ret = 0;

	if (*next == input->buf + input->len)
		goto eof;

	if (line_termination) {
		/* Without -z, consume SP and use next argument */
		if (!**next || **next == line_termination)
			return 1;
		if (**next != ' ')
			die("%s %s: expected SP but got: %s",
			    command, refname, *next);
		(*next)++;
		*next = parse_arg(*next, &arg);
		if (arg.len) {
			if (get_sha1(arg.buf, sha1))
				goto invalid;
		} else {
			/* Without -z, an empty value means all zeros: */
			hashclr(sha1);
		}
	} else {
		/* With -z, read the next NUL-terminated line */
		if (**next)
			die("%s %s: expected NUL but got: %s",
			    command, refname, *next);
		(*next)++;
		if (*next == input->buf + input->len)
			goto eof;
		strbuf_addstr(&arg, *next);
		*next += arg.len;

		if (arg.len) {
			if (get_sha1(arg.buf, sha1))
				goto invalid;
		} else if (flags & PARSE_SHA1_ALLOW_EMPTY) {
			/* With -z, treat an empty value as all zeros: */
			warning("%s %s: missing <newvalue>, treating as zero",
				command, refname);
			hashclr(sha1);
		} else {
			/*
			 * With -z, an empty non-required value means
			 * unspecified:
			 */
			ret = 1;
		}
	}

	strbuf_release(&arg);

	return ret;

 invalid:
	die(flags & PARSE_SHA1_OLD ?
	    "%s %s: invalid <oldvalue>: %s" :
	    "%s %s: invalid <newvalue>: %s",
	    command, refname, arg.buf);

 eof:
	die(flags & PARSE_SHA1_OLD ?
	    "%s %s: unexpected end of input when reading <oldvalue>" :
	    "%s %s: unexpected end of input when reading <newvalue>",
	    command, refname);
}


/*
 * The following five parse_cmd_*() functions parse the corresponding
 * command.  In each case, next points at the character following the
 * command name and the following space.  They each return a pointer
 * to the character terminating the command, and die with an
 * explanatory message if there are any parsing problems.  All of
 * these functions handle either text or binary format input,
 * depending on how line_termination is set.
 */

static const char *parse_cmd_update(struct strbuf *input, const char *next)
{
	struct strbuf err = STRBUF_INIT;
	char *refname;
	unsigned char new_sha1[20];
	unsigned char old_sha1[20];
	int have_old;

	refname = parse_refname(input, &next);
	if (!refname)
		die("update: missing <ref>");

	if (parse_next_sha1(input, &next, new_sha1, "update", refname,
			    PARSE_SHA1_ALLOW_EMPTY))
		die("update %s: missing <newvalue>", refname);

	have_old = !parse_next_sha1(input, &next, old_sha1, "update", refname,
				    PARSE_SHA1_OLD);

	if (*next != line_termination)
		die("update %s: extra input: %s", refname, next);

	if (ref_transaction_update(transaction, refname, new_sha1, old_sha1,
				   update_flags, have_old, &err))
		die("%s", err.buf);

	update_flags = 0;
	free(refname);
	strbuf_release(&err);

	return next;
}

static const char *parse_cmd_create(struct strbuf *input, const char *next)
{
	struct strbuf err = STRBUF_INIT;
	char *refname;
	unsigned char new_sha1[20];

	refname = parse_refname(input, &next);
	if (!refname)
		die("create: missing <ref>");

	if (parse_next_sha1(input, &next, new_sha1, "create", refname, 0))
		die("create %s: missing <newvalue>", refname);

	if (is_null_sha1(new_sha1))
		die("create %s: zero <newvalue>", refname);

	if (*next != line_termination)
		die("create %s: extra input: %s", refname, next);

	if (ref_transaction_create(transaction, refname, new_sha1,
				   update_flags, &err))
		die("%s", err.buf);

	update_flags = 0;
	free(refname);
	strbuf_release(&err);

	return next;
}

static const char *parse_cmd_delete(struct strbuf *input, const char *next)
{
	struct strbuf err = STRBUF_INIT;
	char *refname;
	unsigned char old_sha1[20];
	int have_old;

	refname = parse_refname(input, &next);
	if (!refname)
		die("delete: missing <ref>");

	if (parse_next_sha1(input, &next, old_sha1, "delete", refname,
			    PARSE_SHA1_OLD)) {
		have_old = 0;
	} else {
		if (is_null_sha1(old_sha1))
			die("delete %s: zero <oldvalue>", refname);
		have_old = 1;
	}

	if (*next != line_termination)
		die("delete %s: extra input: %s", refname, next);

	if (ref_transaction_delete(transaction, refname, old_sha1,
				   update_flags, have_old, &err))
		die("%s", err.buf);

	update_flags = 0;
	free(refname);
	strbuf_release(&err);

	return next;
}

static const char *parse_cmd_verify(struct strbuf *input, const char *next)
{
	struct strbuf err = STRBUF_INIT;
	char *refname;
	unsigned char new_sha1[20];
	unsigned char old_sha1[20];
	int have_old;

	refname = parse_refname(input, &next);
	if (!refname)
		die("verify: missing <ref>");

	if (parse_next_sha1(input, &next, old_sha1, "verify", refname,
			    PARSE_SHA1_OLD)) {
		hashclr(new_sha1);
		have_old = 0;
	} else {
		hashcpy(new_sha1, old_sha1);
		have_old = 1;
	}

	if (*next != line_termination)
		die("verify %s: extra input: %s", refname, next);

	if (ref_transaction_update(transaction, refname, new_sha1, old_sha1,
				   update_flags, have_old, &err))
		die("%s", err.buf);

	update_flags = 0;
	free(refname);
	strbuf_release(&err);

	return next;
}

static const char *parse_cmd_option(struct strbuf *input, const char *next)
{
	if (!strncmp(next, "no-deref", 8) && next[8] == line_termination)
		update_flags |= REF_NODEREF;
	else
		die("option unknown: %s", next);
	return next + 8;
}

static void update_refs_stdin(void)
{
	struct strbuf input = STRBUF_INIT;
	const char *next;

	if (strbuf_read(&input, 0, 1000) < 0)
		die_errno("could not read from stdin");
	next = input.buf;
	/* Read each line dispatch its command */
	while (next < input.buf + input.len) {
		if (*next == line_termination)
			die("empty command in input");
		else if (isspace(*next))
			die("whitespace before command: %s", next);
		else if (starts_with(next, "update "))
			next = parse_cmd_update(&input, next + 7);
		else if (starts_with(next, "create "))
			next = parse_cmd_create(&input, next + 7);
		else if (starts_with(next, "delete "))
			next = parse_cmd_delete(&input, next + 7);
		else if (starts_with(next, "verify "))
			next = parse_cmd_verify(&input, next + 7);
		else if (starts_with(next, "option "))
			next = parse_cmd_option(&input, next + 7);
		else
			die("unknown command: %s", next);

		next++;
	}

	strbuf_release(&input);
}

int cmd_update_ref(int argc, const char **argv, const char *prefix)
{
	const char *refname, *oldval, *msg = NULL;
	unsigned char sha1[20], oldsha1[20];
	int delete = 0, no_deref = 0, read_stdin = 0, end_null = 0, flags = 0;
	struct option options[] = {
		OPT_STRING( 'm', NULL, &msg, N_("reason"), N_("reason of the update")),
		OPT_BOOL('d', NULL, &delete, N_("delete the reference")),
		OPT_BOOL( 0 , "no-deref", &no_deref,
					N_("update <refname> not the one it points to")),
		OPT_BOOL('z', NULL, &end_null, N_("stdin has NUL-terminated arguments")),
		OPT_BOOL( 0 , "stdin", &read_stdin, N_("read updates from stdin")),
		OPT_END(),
	};

	git_config(git_default_config, NULL);
	argc = parse_options(argc, argv, prefix, options, git_update_ref_usage,
			     0);
	if (msg && !*msg)
		die("Refusing to perform update with empty message.");

	if (read_stdin) {
		struct strbuf err = STRBUF_INIT;

		transaction = ref_transaction_begin(&err);
		if (!transaction)
			die("%s", err.buf);
		if (delete || no_deref || argc > 0)
			usage_with_options(git_update_ref_usage, options);
		if (end_null)
			line_termination = '\0';
		update_refs_stdin();
		if (ref_transaction_commit(transaction, msg, &err))
			die("%s", err.buf);
		ref_transaction_free(transaction);
		strbuf_release(&err);
		return 0;
	}

	if (end_null)
		usage_with_options(git_update_ref_usage, options);

	if (delete) {
		if (argc < 1 || argc > 2)
			usage_with_options(git_update_ref_usage, options);
		refname = argv[0];
		oldval = argv[1];
	} else {
		const char *value;
		if (argc < 2 || argc > 3)
			usage_with_options(git_update_ref_usage, options);
		refname = argv[0];
		value = argv[1];
		oldval = argv[2];
		if (get_sha1(value, sha1))
			die("%s: not a valid SHA1", value);
	}

	hashclr(oldsha1); /* all-zero hash in case oldval is the empty string */
	if (oldval && *oldval && get_sha1(oldval, oldsha1))
		die("%s: not a valid old SHA1", oldval);

	if (no_deref)
		flags = REF_NODEREF;
	if (delete)
		return delete_ref(refname, oldval ? oldsha1 : NULL, flags);
	else
		return update_ref(msg, refname, sha1, oldval ? oldsha1 : NULL,
				  flags, UPDATE_REFS_DIE_ON_ERR);
}
Commit	Line	Data
66bf85a4 LT	1	#include "cache.h"
66bf85a4 LT	2	#include "refs.h"
854b4629	3	#include "builtin.h"
89942be6	4	#include "parse-options.h"
c750ba95 BK	5	#include "quote.h"
c750ba95 BK	6	#include "argv-array.h"
66bf85a4	7
89942be6	8	static const char * const git_update_ref_usage[] = {
82269505 NTND	9	N_("git update-ref [options] -d <refname> [<oldval>]"),
82269505 NTND	10	N_("git update-ref [options] <refname> <newval> [<oldval>]"),
c750ba95	11	N_("git update-ref [options] --stdin [-z]"),
89942be6 PH	12	NULL
89942be6 PH	13	};
152da3df	14
aebfc133	15	static struct ref_transaction *transaction;
c750ba95 BK	16
	17	static char line_termination = '\n';
	18	static int update_flags;
	19
697a4151 MH	20	/*
	21	* Parse one whitespace- or NUL-terminated, possibly C-quoted argument
	22	* and append the result to arg. Return a pointer to the terminator.
	23	* Die if there is an error in how the argument is C-quoted. This
	24	* function is only used if not -z.
	25	*/
c750ba95 BK	26	static const char parse_arg(const char next, struct strbuf *arg)
c750ba95 BK	27	{
697a4151 MH	28	if (*next == '"') {
	29	const char *orig = next;
	30
	31	if (unquote_c_style(arg, next, &next))
	32	die("badly quoted argument: %s", orig);
	33	if (next && !isspace(next))
	34	die("unexpected character after quoted argument: %s", orig);
	35	} else {
c750ba95 BK	36	while (next && !isspace(next))
c750ba95 BK	37	strbuf_addch(arg, *next++);
697a4151	38	}
c750ba95	39
c750ba95 BK	40	return next;
	41	}
	42
e23d8435	43	/*
ed410e61 MH	44	* Parse the reference name immediately after "command SP". If not
	45	* -z, then handle C-quoting. Return a pointer to a newly allocated
	46	* string containing the name of the reference, or NULL if there was
	47	* an error. Update *next to point at the character that terminates
	48	* the argument. Die if C-quoting is malformed or the reference name
	49	* is invalid.
e23d8435	50	*/
ed410e61	51	static char parse_refname(struct strbuf input, const char **next)
c750ba95	52	{
ed410e61 MH	53	struct strbuf ref = STRBUF_INIT;
ed410e61 MH	54
c750ba95 BK	55	if (line_termination) {
c750ba95 BK	56	/* Without -z, use the next argument */
ed410e61	57	next = parse_arg(next, &ref);
c750ba95	58	} else {
e23d8435	59	/* With -z, use everything up to the next NUL */
ed410e61 MH	60	strbuf_addstr(&ref, *next);
	61	*next += ref.len;
	62	}
	63
	64	if (!ref.len) {
	65	strbuf_release(&ref);
	66	return NULL;
c750ba95	67	}
ed410e61 MH	68
	69	if (check_refname_format(ref.buf, REFNAME_ALLOW_ONELEVEL))
	70	die("invalid ref format: %s", ref.buf);
	71
	72	return strbuf_detach(&ref, NULL);
c750ba95 BK	73	}
c750ba95 BK	74
e23d8435	75	/*
3afcc463 MH	76	* The value being parsed is <oldvalue> (as opposed to <newvalue>; the
	77	* difference affects which error messages are generated):
	78	*/
	79	#define PARSE_SHA1_OLD 0x01
	80
	81	/*
	82	* For backwards compatibility, accept an empty string for update's
	83	* <newvalue> in binary mode to be equivalent to specifying zeros.
	84	*/
	85	#define PARSE_SHA1_ALLOW_EMPTY 0x02
	86
	87	/*
	88	* Parse an argument separator followed by the next argument, if any.
	89	* If there is an argument, convert it to a SHA-1, write it to sha1,
	90	* set *next to point at the character terminating the argument, and
e23d8435	91	* return 0. If there is no argument at all (not even the empty
3afcc463 MH	92	* string), return 1 and leave *next unchanged. If the value is
	93	* provided but cannot be converted to a SHA-1, die. flags can
	94	* include PARSE_SHA1_OLD and/or PARSE_SHA1_ALLOW_EMPTY.
e23d8435	95	*/
3afcc463 MH	96	static int parse_next_sha1(struct strbuf input, const char *next,
	97	unsigned char *sha1,
	98	const char command, const char refname,
	99	int flags)
c750ba95	100	{
3afcc463 MH	101	struct strbuf arg = STRBUF_INIT;
	102	int ret = 0;
	103
	104	if (*next == input->buf + input->len)
	105	goto eof;
	106
c750ba95 BK	107	if (line_termination) {
c750ba95 BK	108	/* Without -z, consume SP and use next argument */
e23d8435	109	if (!next \|\| next == line_termination)
3afcc463	110	return 1;
e23d8435	111	if (**next != ' ')
3afcc463 MH	112	die("%s %s: expected SP but got: %s",
3afcc463 MH	113	command, refname, *next);
e23d8435	114	(*next)++;
3afcc463 MH	115	next = parse_arg(next, &arg);
	116	if (arg.len) {
	117	if (get_sha1(arg.buf, sha1))
	118	goto invalid;
	119	} else {
	120	/* Without -z, an empty value means all zeros: */
	121	hashclr(sha1);
	122	}
c750ba95 BK	123	} else {
c750ba95 BK	124	/* With -z, read the next NUL-terminated line */
e23d8435	125	if (**next)
3afcc463 MH	126	die("%s %s: expected NUL but got: %s",
3afcc463 MH	127	command, refname, *next);
e23d8435 MH	128	(*next)++;
e23d8435 MH	129	if (*next == input->buf + input->len)
3afcc463 MH	130	goto eof;
	131	strbuf_addstr(&arg, *next);
	132	*next += arg.len;
	133
	134	if (arg.len) {
	135	if (get_sha1(arg.buf, sha1))
	136	goto invalid;
	137	} else if (flags & PARSE_SHA1_ALLOW_EMPTY) {
	138	/* With -z, treat an empty value as all zeros: */
1fbd5049 MH	139	warning("%s %s: missing <newvalue>, treating as zero",
1fbd5049 MH	140	command, refname);
3afcc463 MH	141	hashclr(sha1);
	142	} else {
	143	/*
	144	* With -z, an empty non-required value means
	145	* unspecified:
	146	*/
	147	ret = 1;
	148	}
c750ba95	149	}
3afcc463 MH	150
	151	strbuf_release(&arg);
	152
	153	return ret;
	154
	155	invalid:
	156	die(flags & PARSE_SHA1_OLD ?
	157	"%s %s: invalid <oldvalue>: %s" :
	158	"%s %s: invalid <newvalue>: %s",
	159	command, refname, arg.buf);
	160
	161	eof:
	162	die(flags & PARSE_SHA1_OLD ?
726f6916 MH	163	"%s %s: unexpected end of input when reading <oldvalue>" :
726f6916 MH	164	"%s %s: unexpected end of input when reading <newvalue>",
3afcc463	165	command, refname);
c750ba95 BK	166	}
c750ba95 BK	167
e23d8435 MH	168
	169	/*
	170	* The following five parse_cmd_*() functions parse the corresponding
	171	* command. In each case, next points at the character following the
	172	* command name and the following space. They each return a pointer
	173	* to the character terminating the command, and die with an
	174	* explanatory message if there are any parsing problems. All of
	175	* these functions handle either text or binary format input,
	176	* depending on how line_termination is set.
	177	*/
	178
	179	static const char parse_cmd_update(struct strbuf input, const char *next)
c750ba95	180	{
ab5ac957	181	struct strbuf err = STRBUF_INIT;
aebfc133 MH	182	char *refname;
	183	unsigned char new_sha1[20];
	184	unsigned char old_sha1[20];
	185	int have_old;
c750ba95	186
aebfc133 MH	187	refname = parse_refname(input, &next);
aebfc133 MH	188	if (!refname)
f11b09fb	189	die("update: missing <ref>");
c750ba95	190
aebfc133	191	if (parse_next_sha1(input, &next, new_sha1, "update", refname,
3afcc463	192	PARSE_SHA1_ALLOW_EMPTY))
aebfc133	193	die("update %s: missing <newvalue>", refname);
c750ba95	194
aebfc133 MH	195	have_old = !parse_next_sha1(input, &next, old_sha1, "update", refname,
aebfc133 MH	196	PARSE_SHA1_OLD);
3afcc463 MH	197
3afcc463 MH	198	if (*next != line_termination)
aebfc133 MH	199	die("update %s: extra input: %s", refname, next);
aebfc133 MH	200
8e34800e RS	201	if (ref_transaction_update(transaction, refname, new_sha1, old_sha1,
	202	update_flags, have_old, &err))
	203	die("%s", err.buf);
aebfc133 MH	204
	205	update_flags = 0;
	206	free(refname);
ab5ac957	207	strbuf_release(&err);
c750ba95	208
e23d8435	209	return next;
c750ba95 BK	210	}
c750ba95 BK	211
e23d8435	212	static const char parse_cmd_create(struct strbuf input, const char *next)
c750ba95	213	{
ab5ac957	214	struct strbuf err = STRBUF_INIT;
aebfc133 MH	215	char *refname;
aebfc133 MH	216	unsigned char new_sha1[20];
c750ba95	217
aebfc133 MH	218	refname = parse_refname(input, &next);
aebfc133 MH	219	if (!refname)
f11b09fb	220	die("create: missing <ref>");
c750ba95	221
aebfc133 MH	222	if (parse_next_sha1(input, &next, new_sha1, "create", refname, 0))
aebfc133 MH	223	die("create %s: missing <newvalue>", refname);
e23d8435	224
aebfc133 MH	225	if (is_null_sha1(new_sha1))
aebfc133 MH	226	die("create %s: zero <newvalue>", refname);
c750ba95	227
e23d8435	228	if (*next != line_termination)
aebfc133 MH	229	die("create %s: extra input: %s", refname, next);
aebfc133 MH	230
b416af5b RS	231	if (ref_transaction_create(transaction, refname, new_sha1,
	232	update_flags, &err))
	233	die("%s", err.buf);
aebfc133 MH	234
	235	update_flags = 0;
	236	free(refname);
ab5ac957	237	strbuf_release(&err);
e23d8435 MH	238
e23d8435 MH	239	return next;
c750ba95 BK	240	}
c750ba95 BK	241
e23d8435	242	static const char parse_cmd_delete(struct strbuf input, const char *next)
c750ba95	243	{
ab5ac957	244	struct strbuf err = STRBUF_INIT;
aebfc133 MH	245	char *refname;
	246	unsigned char old_sha1[20];
	247	int have_old;
c750ba95	248
aebfc133 MH	249	refname = parse_refname(input, &next);
aebfc133 MH	250	if (!refname)
f11b09fb	251	die("delete: missing <ref>");
c750ba95	252
aebfc133 MH	253	if (parse_next_sha1(input, &next, old_sha1, "delete", refname,
	254	PARSE_SHA1_OLD)) {
	255	have_old = 0;
3afcc463	256	} else {
aebfc133 MH	257	if (is_null_sha1(old_sha1))
	258	die("delete %s: zero <oldvalue>", refname);
	259	have_old = 1;
3afcc463	260	}
c750ba95	261
e23d8435	262	if (*next != line_termination)
aebfc133 MH	263	die("delete %s: extra input: %s", refname, next);
aebfc133 MH	264
8c8bdc0d RS	265	if (ref_transaction_delete(transaction, refname, old_sha1,
	266	update_flags, have_old, &err))
	267	die("%s", err.buf);
aebfc133 MH	268
	269	update_flags = 0;
	270	free(refname);
ab5ac957	271	strbuf_release(&err);
e23d8435 MH	272
e23d8435 MH	273	return next;
c750ba95 BK	274	}
c750ba95 BK	275
e23d8435	276	static const char parse_cmd_verify(struct strbuf input, const char *next)
c750ba95	277	{
ab5ac957	278	struct strbuf err = STRBUF_INIT;
aebfc133 MH	279	char *refname;
	280	unsigned char new_sha1[20];
	281	unsigned char old_sha1[20];
	282	int have_old;
c750ba95	283
aebfc133 MH	284	refname = parse_refname(input, &next);
aebfc133 MH	285	if (!refname)
f11b09fb	286	die("verify: missing <ref>");
c750ba95	287
aebfc133 MH	288	if (parse_next_sha1(input, &next, old_sha1, "verify", refname,
	289	PARSE_SHA1_OLD)) {
	290	hashclr(new_sha1);
	291	have_old = 0;
3afcc463	292	} else {
aebfc133 MH	293	hashcpy(new_sha1, old_sha1);
aebfc133 MH	294	have_old = 1;
3afcc463	295	}
c750ba95	296
e23d8435	297	if (*next != line_termination)
aebfc133 MH	298	die("verify %s: extra input: %s", refname, next);
aebfc133 MH	299
8e34800e RS	300	if (ref_transaction_update(transaction, refname, new_sha1, old_sha1,
	301	update_flags, have_old, &err))
	302	die("%s", err.buf);
aebfc133 MH	303
	304	update_flags = 0;
	305	free(refname);
ab5ac957	306	strbuf_release(&err);
e23d8435 MH	307
e23d8435 MH	308	return next;
c750ba95 BK	309	}
c750ba95 BK	310
e23d8435	311	static const char parse_cmd_option(struct strbuf input, const char *next)
c750ba95	312	{
e23d8435	313	if (!strncmp(next, "no-deref", 8) && next[8] == line_termination)
c750ba95 BK	314	update_flags \|= REF_NODEREF;
	315	else
	316	die("option unknown: %s", next);
e23d8435	317	return next + 8;
c750ba95 BK	318	}
	319
	320	static void update_refs_stdin(void)
	321	{
e23d8435 MH	322	struct strbuf input = STRBUF_INIT;
e23d8435 MH	323	const char *next;
c750ba95	324
e23d8435 MH	325	if (strbuf_read(&input, 0, 1000) < 0)
	326	die_errno("could not read from stdin");
	327	next = input.buf;
c750ba95	328	/* Read each line dispatch its command */
e23d8435 MH	329	while (next < input.buf + input.len) {
e23d8435 MH	330	if (*next == line_termination)
c750ba95	331	die("empty command in input");
e23d8435 MH	332	else if (isspace(*next))
	333	die("whitespace before command: %s", next);
	334	else if (starts_with(next, "update "))
	335	next = parse_cmd_update(&input, next + 7);
	336	else if (starts_with(next, "create "))
	337	next = parse_cmd_create(&input, next + 7);
	338	else if (starts_with(next, "delete "))
	339	next = parse_cmd_delete(&input, next + 7);
	340	else if (starts_with(next, "verify "))
	341	next = parse_cmd_verify(&input, next + 7);
	342	else if (starts_with(next, "option "))
	343	next = parse_cmd_option(&input, next + 7);
c750ba95	344	else
e23d8435 MH	345	die("unknown command: %s", next);
	346
	347	next++;
	348	}
c750ba95	349
e23d8435	350	strbuf_release(&input);
c750ba95 BK	351	}
c750ba95 BK	352
a633fca0	353	int cmd_update_ref(int argc, const char *argv, const char prefix)
66bf85a4	354	{
f877fd82	355	const char refname, oldval, *msg = NULL;
5b16b090	356	unsigned char sha1[20], oldsha1[20];
c750ba95	357	int delete = 0, no_deref = 0, read_stdin = 0, end_null = 0, flags = 0;
89942be6	358	struct option options[] = {
82269505	359	OPT_STRING( 'm', NULL, &msg, N_("reason"), N_("reason of the update")),
d5d09d47 SB	360	OPT_BOOL('d', NULL, &delete, N_("delete the reference")),
d5d09d47 SB	361	OPT_BOOL( 0 , "no-deref", &no_deref,
82269505	362	N_("update <refname> not the one it points to")),
9a86b899 JH	363	OPT_BOOL('z', NULL, &end_null, N_("stdin has NUL-terminated arguments")),
9a86b899 JH	364	OPT_BOOL( 0 , "stdin", &read_stdin, N_("read updates from stdin")),
89942be6 PH	365	OPT_END(),
89942be6 PH	366	};
66bf85a4	367
ef90d6d4	368	git_config(git_default_config, NULL);
37782920 SB	369	argc = parse_options(argc, argv, prefix, options, git_update_ref_usage,
37782920 SB	370	0);
89942be6 PH	371	if (msg && !*msg)
89942be6 PH	372	die("Refusing to perform update with empty message.");
5b16b090	373
c750ba95	374	if (read_stdin) {
ab5ac957 JN	375	struct strbuf err = STRBUF_INIT;
ab5ac957 JN	376
93a644ea RS	377	transaction = ref_transaction_begin(&err);
	378	if (!transaction)
	379	die("%s", err.buf);
c750ba95 BK	380	if (delete \|\| no_deref \|\| argc > 0)
	381	usage_with_options(git_update_ref_usage, options);
	382	if (end_null)
	383	line_termination = '\0';
	384	update_refs_stdin();
01319837	385	if (ref_transaction_commit(transaction, msg, &err))
8bcd3748	386	die("%s", err.buf);
33f9fc59	387	ref_transaction_free(transaction);
93a644ea	388	strbuf_release(&err);
8bcd3748	389	return 0;
c750ba95 BK	390	}
	391
	392	if (end_null)
	393	usage_with_options(git_update_ref_usage, options);
	394
ac5409e4	395	if (delete) {
3fe8dce6	396	if (argc < 1 \|\| argc > 2)
973a70ea KW	397	usage_with_options(git_update_ref_usage, options);
	398	refname = argv[0];
	399	oldval = argv[1];
	400	} else {
	401	const char *value;
	402	if (argc < 2 \|\| argc > 3)
89942be6	403	usage_with_options(git_update_ref_usage, options);
973a70ea KW	404	refname = argv[0];
	405	value = argv[1];
	406	oldval = argv[2];
	407	if (get_sha1(value, sha1))
	408	die("%s: not a valid SHA1", value);
ac5409e4 JH	409	}
ac5409e4 JH	410
973a70ea	411	hashclr(oldsha1); /* all-zero hash in case oldval is the empty string */
ac5409e4	412	if (oldval && *oldval && get_sha1(oldval, oldsha1))
66bf85a4 LT	413	die("%s: not a valid old SHA1", oldval);
66bf85a4 LT	414
569740bd MV	415	if (no_deref)
569740bd MV	416	flags = REF_NODEREF;
973a70ea	417	if (delete)
569740bd	418	return delete_ref(refname, oldval ? oldsha1 : NULL, flags);
973a70ea KW	419	else
973a70ea KW	420	return update_ref(msg, refname, sha1, oldval ? oldsha1 : NULL,
f4124112	421	flags, UPDATE_REFS_DIE_ON_ERR);
66bf85a4	422	}