builtin/tag.c - git - Git at Google

 /*
  * Builtin "git tag"
  *
  * Copyright (c) 2007 Kristian Høgsberg <krh@redhat.com>,
  *                    Carlos Rica <jasampler@gmail.com>
  * Based on git-tag.sh and mktag.c by Linus Torvalds.
  */

 #include "cache.h"
 #include "config.h"
 #include "builtin.h"
 #include "refs.h"
 #include "tag.h"
 #include "run-command.h"
 #include "parse-options.h"
 #include "diff.h"
 #include "revision.h"
 #include "gpg-interface.h"
 #include "sha1-array.h"
 #include "column.h"
 #include "ref-filter.h"

 static const char * const git_tag_usage[] = {
 	N_("git tag [-a | -s | -u <key-id>] [-f] [-m <msg> | -F <file>] <tagname> [<head>]"),
 	N_("git tag -d <tagname>..."),
 	N_("git tag -l [-n[<num>]] [--contains <commit>] [--no-contains <commit>] [--points-at <object>]"
 		"\n\t\t[--format=<format>] [--[no-]merged [<commit>]] [<pattern>...]"),
 	N_("git tag -v [--format=<format>] <tagname>..."),
 	NULL
 };

 static unsigned int colopts;
 static int force_sign_annotate;

 static int list_tags(struct ref_filter *filter, struct ref_sorting *sorting,
 		     struct ref_format *format)
 {
 	struct ref_array array;
 	char *to_free = NULL;
 	int i;

 	memset(&array, 0, sizeof(array));

 	if (filter->lines == -1)
 		filter->lines = 0;

 	if (!format->format) {
 		if (filter->lines) {
 			to_free = xstrfmt("%s %%(contents:lines=%d)",
 					  "%(align:15)%(refname:lstrip=2)%(end)",
 					  filter->lines);
 			format->format = to_free;
 		} else
 			format->format = "%(refname:lstrip=2)";
 	}

 	if (verify_ref_format(format))
 		die(_("unable to parse format string"));
 	filter->with_commit_tag_algo = 1;
 	filter_refs(&array, filter, FILTER_REFS_TAGS);
 	ref_array_sort(sorting, &array);

 	for (i = 0; i < array.nr; i++)
 		show_ref_array_item(array.items[i], format);
 	ref_array_clear(&array);
 	free(to_free);

 	return 0;
 }

 typedef int (*each_tag_name_fn)(const char *name, const char *ref,
 				const struct object_id *oid, const void *cb_data);

 static int for_each_tag_name(const char **argv, each_tag_name_fn fn,
 			     const void *cb_data)
 {
 	const char **p;
 	struct strbuf ref = STRBUF_INIT;
 	int had_error = 0;
 	struct object_id oid;

 	for (p = argv; *p; p++) {
 		strbuf_reset(&ref);
 		strbuf_addf(&ref, "refs/tags/%s", *p);
 		if (read_ref(ref.buf, oid.hash)) {
 			error(_("tag '%s' not found."), *p);
 			had_error = 1;
 			continue;
 		}
 		if (fn(*p, ref.buf, &oid, cb_data))
 			had_error = 1;
 	}
 	strbuf_release(&ref);
 	return had_error;
 }

 static int delete_tag(const char *name, const char *ref,
 		      const struct object_id *oid, const void *cb_data)
 {
 	if (delete_ref(NULL, ref, oid->hash, 0))
 		return 1;
 	printf(_("Deleted tag '%s' (was %s)\n"), name, find_unique_abbrev(oid->hash, DEFAULT_ABBREV));
 	return 0;
 }

 static int verify_tag(const char *name, const char *ref,
 		      const struct object_id *oid, const void *cb_data)
 {
 	int flags;
 	const struct ref_format *format = cb_data;
 	flags = GPG_VERIFY_VERBOSE;

 	if (format->format)
 		flags = GPG_VERIFY_OMIT_STATUS;

 	if (gpg_verify_tag(oid->hash, name, flags))
 		return -1;

 	if (format->format)
 		pretty_print_ref(name, oid->hash, format);

 	return 0;
 }

 static int do_sign(struct strbuf *buffer)
 {
 	return sign_buffer(buffer, buffer, get_signing_key());
 }

 static const char tag_template[] =
 	N_("\nWrite a message for tag:\n  %s\n"
 	"Lines starting with '%c' will be ignored.\n");

 static const char tag_template_nocleanup[] =
 	N_("\nWrite a message for tag:\n  %s\n"
 	"Lines starting with '%c' will be kept; you may remove them"
 	" yourself if you want to.\n");

 static int git_tag_config(const char *var, const char *value, void *cb)
 {
 	int status;
 	struct ref_sorting **sorting_tail = (struct ref_sorting **)cb;

 	if (!strcmp(var, "tag.sort")) {
 		if (!value)
 			return config_error_nonbool(var);
 		parse_ref_sorting(sorting_tail, value);
 		return 0;
 	}

 	status = git_gpg_config(var, value, cb);
 	if (status)
 		return status;
 	if (!strcmp(var, "tag.forcesignannotated")) {
 		force_sign_annotate = git_config_bool(var, value);
 		return 0;
 	}

 	if (starts_with(var, "column."))
 		return git_column_config(var, value, "tag", &colopts);
 	return git_color_default_config(var, value, cb);
 }

 static void write_tag_body(int fd, const struct object_id *oid)
 {
 	unsigned long size;
 	enum object_type type;
 	char *buf, *sp;

 	buf = read_sha1_file(oid->hash, &type, &size);
 	if (!buf)
 		return;
 	/* skip header */
 	sp = strstr(buf, "\n\n");

 	if (!sp || !size || type != OBJ_TAG) {
 		free(buf);
 		return;
 	}
 	sp += 2; /* skip the 2 LFs */
 	write_or_die(fd, sp, parse_signature(sp, buf + size - sp));

 	free(buf);
 }

 static int build_tag_object(struct strbuf *buf, int sign, struct object_id *result)
 {
 	if (sign && do_sign(buf) < 0)
 		return error(_("unable to sign the tag"));
 	if (write_sha1_file(buf->buf, buf->len, tag_type, result->hash) < 0)
 		return error(_("unable to write tag file"));
 	return 0;
 }

 struct create_tag_options {
 	unsigned int message_given:1;
 	unsigned int sign;
 	enum {
 		CLEANUP_NONE,
 		CLEANUP_SPACE,
 		CLEANUP_ALL
 	} cleanup_mode;
 };

 static void create_tag(const struct object_id *object, const char *tag,
 		       struct strbuf *buf, struct create_tag_options *opt,
 		       struct object_id *prev, struct object_id *result)
 {
 	enum object_type type;
 	struct strbuf header = STRBUF_INIT;
 	char *path = NULL;

 	type = sha1_object_info(object->hash, NULL);
 	if (type <= OBJ_NONE)
 	    die(_("bad object type."));

 	strbuf_addf(&header,
 		    "object %s\n"
 		    "type %s\n"
 		    "tag %s\n"
 		    "tagger %s\n\n",
 		    oid_to_hex(object),
 		    typename(type),
 		    tag,
 		    git_committer_info(IDENT_STRICT));

 	if (!opt->message_given) {
 		int fd;

 		/* write the template message before editing: */
 		path = git_pathdup("TAG_EDITMSG");
 		fd = open(path, O_CREAT | O_TRUNC | O_WRONLY, 0600);
 		if (fd < 0)
 			die_errno(_("could not create file '%s'"), path);

 		if (!is_null_oid(prev)) {
 			write_tag_body(fd, prev);
 		} else {
 			struct strbuf buf = STRBUF_INIT;
 			strbuf_addch(&buf, '\n');
 			if (opt->cleanup_mode == CLEANUP_ALL)
 				strbuf_commented_addf(&buf, _(tag_template), tag, comment_line_char);
 			else
 				strbuf_commented_addf(&buf, _(tag_template_nocleanup), tag, comment_line_char);
 			write_or_die(fd, buf.buf, buf.len);
 			strbuf_release(&buf);
 		}
 		close(fd);

 		if (launch_editor(path, buf, NULL)) {
 			fprintf(stderr,
 			_("Please supply the message using either -m or -F option.\n"));
 			exit(1);
 		}
 	}

 	if (opt->cleanup_mode != CLEANUP_NONE)
 		strbuf_stripspace(buf, opt->cleanup_mode == CLEANUP_ALL);

 	if (!opt->message_given && !buf->len)
 		die(_("no tag message?"));

 	strbuf_insert(buf, 0, header.buf, header.len);
 	strbuf_release(&header);

 	if (build_tag_object(buf, opt->sign, result) < 0) {
 		if (path)
 			fprintf(stderr, _("The tag message has been left in %s\n"),
 				path);
 		exit(128);
 	}
 	if (path) {
 		unlink_or_warn(path);
 		free(path);
 	}
 }

 static void create_reflog_msg(const struct object_id *oid, struct strbuf *sb)
 {
 	enum object_type type;
 	struct commit *c;
 	char *buf;
 	unsigned long size;
 	int subject_len = 0;
 	const char *subject_start;

 	char *rla = getenv("GIT_REFLOG_ACTION");
 	if (rla) {
 		strbuf_addstr(sb, rla);
 	} else {
 		strbuf_addstr(sb, "tag: tagging ");
 		strbuf_add_unique_abbrev(sb, oid->hash, DEFAULT_ABBREV);
 	}

 	strbuf_addstr(sb, " (");
 	type = sha1_object_info(oid->hash, NULL);
 	switch (type) {
 	default:
 		strbuf_addstr(sb, "object of unknown type");
 		break;
 	case OBJ_COMMIT:
 		if ((buf = read_sha1_file(oid->hash, &type, &size)) != NULL) {
 			subject_len = find_commit_subject(buf, &subject_start);
 			strbuf_insert(sb, sb->len, subject_start, subject_len);
 		} else {
 			strbuf_addstr(sb, "commit object");
 		}
 		free(buf);

 		if ((c = lookup_commit_reference(oid)) != NULL)
 			strbuf_addf(sb, ", %s", show_date(c->date, 0, DATE_MODE(SHORT)));
 		break;
 	case OBJ_TREE:
 		strbuf_addstr(sb, "tree object");
 		break;
 	case OBJ_BLOB:
 		strbuf_addstr(sb, "blob object");
 		break;
 	case OBJ_TAG:
 		strbuf_addstr(sb, "other tag object");
 		break;
 	}
 	strbuf_addch(sb, ')');
 }

 struct msg_arg {
 	int given;
 	struct strbuf buf;
 };

 static int parse_msg_arg(const struct option *opt, const char *arg, int unset)
 {
 	struct msg_arg *msg = opt->value;

 	if (!arg)
 		return -1;
 	if (msg->buf.len)
 		strbuf_addstr(&(msg->buf), "\n\n");
 	strbuf_addstr(&(msg->buf), arg);
 	msg->given = 1;
 	return 0;
 }

 static int strbuf_check_tag_ref(struct strbuf *sb, const char *name)
 {
 	if (name[0] == '-')
 		return -1;

 	strbuf_reset(sb);
 	strbuf_addf(sb, "refs/tags/%s", name);

 	return check_refname_format(sb->buf, 0);
 }

 int cmd_tag(int argc, const char **argv, const char *prefix)
 {
 	struct strbuf buf = STRBUF_INIT;
 	struct strbuf ref = STRBUF_INIT;
 	struct strbuf reflog_msg = STRBUF_INIT;
 	struct object_id object, prev;
 	const char *object_ref, *tag;
 	struct create_tag_options opt;
 	char *cleanup_arg = NULL;
 	int create_reflog = 0;
 	int annotate = 0, force = 0;
 	int cmdmode = 0, create_tag_object = 0;
 	const char *msgfile = NULL, *keyid = NULL;
 	struct msg_arg msg = { 0, STRBUF_INIT };
 	struct ref_transaction *transaction;
 	struct strbuf err = STRBUF_INIT;
 	struct ref_filter filter;
 	static struct ref_sorting *sorting = NULL, **sorting_tail = &sorting;
 	struct ref_format format = REF_FORMAT_INIT;
 	int icase = 0;
 	struct option options[] = {
 		OPT_CMDMODE('l', "list", &cmdmode, N_("list tag names"), 'l'),
 		{ OPTION_INTEGER, 'n', NULL, &filter.lines, N_("n"),
 				N_("print <n> lines of each tag message"),
 				PARSE_OPT_OPTARG, NULL, 1 },
 		OPT_CMDMODE('d', "delete", &cmdmode, N_("delete tags"), 'd'),
 		OPT_CMDMODE('v', "verify", &cmdmode, N_("verify tags"), 'v'),

 		OPT_GROUP(N_("Tag creation options")),
 		OPT_BOOL('a', "annotate", &annotate,
 					N_("annotated tag, needs a message")),
 		OPT_CALLBACK('m', "message", &msg, N_("message"),
 			     N_("tag message"), parse_msg_arg),
 		OPT_FILENAME('F', "file", &msgfile, N_("read message from file")),
 		OPT_BOOL('s', "sign", &opt.sign, N_("annotated and GPG-signed tag")),
 		OPT_STRING(0, "cleanup", &cleanup_arg, N_("mode"),
 			N_("how to strip spaces and #comments from message")),
 		OPT_STRING('u', "local-user", &keyid, N_("key-id"),
 					N_("use another key to sign the tag")),
 		OPT__FORCE(&force, N_("replace the tag if exists")),
 		OPT_BOOL(0, "create-reflog", &create_reflog, N_("create a reflog")),

 		OPT_GROUP(N_("Tag listing options")),
 		OPT_COLUMN(0, "column", &colopts, N_("show tag list in columns")),
 		OPT_CONTAINS(&filter.with_commit, N_("print only tags that contain the commit")),
 		OPT_NO_CONTAINS(&filter.no_commit, N_("print only tags that don't contain the commit")),
 		OPT_WITH(&filter.with_commit, N_("print only tags that contain the commit")),
 		OPT_WITHOUT(&filter.no_commit, N_("print only tags that don't contain the commit")),
 		OPT_MERGED(&filter, N_("print only tags that are merged")),
 		OPT_NO_MERGED(&filter, N_("print only tags that are not merged")),
 		OPT_CALLBACK(0 , "sort", sorting_tail, N_("key"),
 			     N_("field name to sort on"), &parse_opt_ref_sorting),
 		{
 			OPTION_CALLBACK, 0, "points-at", &filter.points_at, N_("object"),
 			N_("print only tags of the object"), PARSE_OPT_LASTARG_DEFAULT,
 			parse_opt_object_name, (intptr_t) "HEAD"
 		},
 		OPT_STRING(  0 , "format", &format.format, N_("format"),
 			   N_("format to use for the output")),
 		OPT__COLOR(&format.use_color, N_("respect format colors")),
 		OPT_BOOL('i', "ignore-case", &icase, N_("sorting and filtering are case insensitive")),
 		OPT_END()
 	};

 	setup_ref_filter_porcelain_msg();

 	git_config(git_tag_config, sorting_tail);

 	memset(&opt, 0, sizeof(opt));
 	memset(&filter, 0, sizeof(filter));
 	filter.lines = -1;

 	argc = parse_options(argc, argv, prefix, options, git_tag_usage, 0);

 	if (keyid) {
 		opt.sign = 1;
 		set_signing_key(keyid);
 	}
 	create_tag_object = (opt.sign || annotate || msg.given || msgfile);

 	if (!cmdmode) {
 		if (argc == 0)
 			cmdmode = 'l';
 		else if (filter.with_commit || filter.no_commit ||
 			 filter.points_at.nr || filter.merge_commit ||
 			 filter.lines != -1)
 			cmdmode = 'l';
 	}

 	if (cmdmode == 'l')
 		setup_auto_pager("tag", 1);

 	if ((create_tag_object || force) && (cmdmode != 0))
 		usage_with_options(git_tag_usage, options);

 	finalize_colopts(&colopts, -1);
 	if (cmdmode == 'l' && filter.lines != -1) {
 		if (explicitly_enable_column(colopts))
 			die(_("--column and -n are incompatible"));
 		colopts = 0;
 	}
 	if (!sorting)
 		sorting = ref_default_sorting();
 	sorting->ignore_case = icase;
 	filter.ignore_case = icase;
 	if (cmdmode == 'l') {
 		int ret;
 		if (column_active(colopts)) {
 			struct column_options copts;
 			memset(&copts, 0, sizeof(copts));
 			copts.padding = 2;
 			run_column_filter(colopts, &copts);
 		}
 		filter.name_patterns = argv;
 		ret = list_tags(&filter, sorting, &format);
 		if (column_active(colopts))
 			stop_column_filter();
 		return ret;
 	}
 	if (filter.lines != -1)
 		die(_("-n option is only allowed in list mode"));
 	if (filter.with_commit)
 		die(_("--contains option is only allowed in list mode"));
 	if (filter.no_commit)
 		die(_("--no-contains option is only allowed in list mode"));
 	if (filter.points_at.nr)
 		die(_("--points-at option is only allowed in list mode"));
 	if (filter.merge_commit)
 		die(_("--merged and --no-merged options are only allowed in list mode"));
 	if (cmdmode == 'd')
 		return for_each_tag_name(argv, delete_tag, NULL);
 	if (cmdmode == 'v') {
 		if (format.format && verify_ref_format(&format))
 			usage_with_options(git_tag_usage, options);
 		return for_each_tag_name(argv, verify_tag, &format);
 	}

 	if (msg.given || msgfile) {
 		if (msg.given && msgfile)
 			die(_("only one -F or -m option is allowed."));
 		if (msg.given)
 			strbuf_addbuf(&buf, &(msg.buf));
 		else {
 			if (!strcmp(msgfile, "-")) {
 				if (strbuf_read(&buf, 0, 1024) < 0)
 					die_errno(_("cannot read '%s'"), msgfile);
 			} else {
 				if (strbuf_read_file(&buf, msgfile, 1024) < 0)
 					die_errno(_("could not open or read '%s'"),
 						msgfile);
 			}
 		}
 	}

 	tag = argv[0];

 	object_ref = argc == 2 ? argv[1] : "HEAD";
 	if (argc > 2)
 		die(_("too many params"));

 	if (get_oid(object_ref, &object))
 		die(_("Failed to resolve '%s' as a valid ref."), object_ref);

 	if (strbuf_check_tag_ref(&ref, tag))
 		die(_("'%s' is not a valid tag name."), tag);

 	if (read_ref(ref.buf, prev.hash))
 		oidclr(&prev);
 	else if (!force)
 		die(_("tag '%s' already exists"), tag);

 	opt.message_given = msg.given || msgfile;

 	if (!cleanup_arg || !strcmp(cleanup_arg, "strip"))
 		opt.cleanup_mode = CLEANUP_ALL;
 	else if (!strcmp(cleanup_arg, "verbatim"))
 		opt.cleanup_mode = CLEANUP_NONE;
 	else if (!strcmp(cleanup_arg, "whitespace"))
 		opt.cleanup_mode = CLEANUP_SPACE;
 	else
 		die(_("Invalid cleanup mode %s"), cleanup_arg);

 	create_reflog_msg(&object, &reflog_msg);

 	if (create_tag_object) {
 		if (force_sign_annotate && !annotate)
 			opt.sign = 1;
 		create_tag(&object, tag, &buf, &opt, &prev, &object);
 	}

 	transaction = ref_transaction_begin(&err);
 	if (!transaction ||
 	    ref_transaction_update(transaction, ref.buf, object.hash, prev.hash,
 				   create_reflog ? REF_FORCE_CREATE_REFLOG : 0,
 				   reflog_msg.buf, &err) ||
 	    ref_transaction_commit(transaction, &err))
 		die("%s", err.buf);
 	ref_transaction_free(transaction);
 	if (force && !is_null_oid(&prev) && oidcmp(&prev, &object))
 		printf(_("Updated tag '%s' (was %s)\n"), tag, find_unique_abbrev(prev.hash, DEFAULT_ABBREV));

 	strbuf_release(&err);
 	strbuf_release(&buf);
 	strbuf_release(&ref);
 	strbuf_release(&reflog_msg);
 	return 0;
 }
	/*
	* Builtin "git tag"
	*
	* Copyright (c) 2007 Kristian Høgsberg <krh@redhat.com>,
	* Carlos Rica <jasampler@gmail.com>
	* Based on git-tag.sh and mktag.c by Linus Torvalds.
	*/

	#include "cache.h"
	#include "config.h"
	#include "builtin.h"
	#include "refs.h"
	#include "tag.h"
	#include "run-command.h"
	#include "parse-options.h"
	#include "diff.h"
	#include "revision.h"
	#include "gpg-interface.h"
	#include "sha1-array.h"
	#include "column.h"
	#include "ref-filter.h"

	static const char * const git_tag_usage[] = {
	N_("git tag [-a \| -s \| -u <key-id>] [-f] [-m <msg> \| -F <file>] <tagname> [<head>]"),
	N_("git tag -d <tagname>..."),
	N_("git tag -l [-n[<num>]] [--contains <commit>] [--no-contains <commit>] [--points-at <object>]"
	"\n\t\t[--format=<format>] [--[no-]merged [<commit>]] [<pattern>...]"),
	N_("git tag -v [--format=<format>] <tagname>..."),
	NULL
	};

	static unsigned int colopts;
	static int force_sign_annotate;

	static int list_tags(struct ref_filter filter, struct ref_sorting sorting,
	struct ref_format *format)
	{
	struct ref_array array;
	char *to_free = NULL;
	int i;

	memset(&array, 0, sizeof(array));

	if (filter->lines == -1)
	filter->lines = 0;

	if (!format->format) {
	if (filter->lines) {
	to_free = xstrfmt("%s %%(contents:lines=%d)",
	"%(align:15)%(refname:lstrip=2)%(end)",
	filter->lines);
	format->format = to_free;
	} else
	format->format = "%(refname:lstrip=2)";
	}

	if (verify_ref_format(format))
	die(_("unable to parse format string"));
	filter->with_commit_tag_algo = 1;
	filter_refs(&array, filter, FILTER_REFS_TAGS);
	ref_array_sort(sorting, &array);

	for (i = 0; i < array.nr; i++)
	show_ref_array_item(array.items[i], format);
	ref_array_clear(&array);
	free(to_free);

	return 0;
	}

	typedef int (each_tag_name_fn)(const char name, const char *ref,
	const struct object_id oid, const void cb_data);

	static int for_each_tag_name(const char **argv, each_tag_name_fn fn,
	const void *cb_data)
	{
	const char **p;
	struct strbuf ref = STRBUF_INIT;
	int had_error = 0;
	struct object_id oid;

	for (p = argv; *p; p++) {
	strbuf_reset(&ref);
	strbuf_addf(&ref, "refs/tags/%s", *p);
	if (read_ref(ref.buf, oid.hash)) {
	error(_("tag '%s' not found."), *p);
	had_error = 1;
	continue;
	}
	if (fn(*p, ref.buf, &oid, cb_data))
	had_error = 1;
	}
	strbuf_release(&ref);
	return had_error;
	}

	static int delete_tag(const char name, const char ref,
	const struct object_id oid, const void cb_data)
	{
	if (delete_ref(NULL, ref, oid->hash, 0))
	return 1;
	printf(_("Deleted tag '%s' (was %s)\n"), name, find_unique_abbrev(oid->hash, DEFAULT_ABBREV));
	return 0;
	}

	static int verify_tag(const char name, const char ref,
	const struct object_id oid, const void cb_data)
	{
	int flags;
	const struct ref_format *format = cb_data;
	flags = GPG_VERIFY_VERBOSE;

	if (format->format)
	flags = GPG_VERIFY_OMIT_STATUS;

	if (gpg_verify_tag(oid->hash, name, flags))
	return -1;

	if (format->format)
	pretty_print_ref(name, oid->hash, format);

	return 0;
	}

	static int do_sign(struct strbuf *buffer)
	{
	return sign_buffer(buffer, buffer, get_signing_key());
	}

	static const char tag_template[] =
	N_("\nWrite a message for tag:\n %s\n"
	"Lines starting with '%c' will be ignored.\n");

	static const char tag_template_nocleanup[] =
	N_("\nWrite a message for tag:\n %s\n"
	"Lines starting with '%c' will be kept; you may remove them"
	" yourself if you want to.\n");

	static int git_tag_config(const char var, const char value, void *cb)
	{
	int status;
	struct ref_sorting sorting_tail = (struct ref_sorting )cb;

	if (!strcmp(var, "tag.sort")) {
	if (!value)
	return config_error_nonbool(var);
	parse_ref_sorting(sorting_tail, value);
	return 0;
	}

	status = git_gpg_config(var, value, cb);
	if (status)
	return status;
	if (!strcmp(var, "tag.forcesignannotated")) {
	force_sign_annotate = git_config_bool(var, value);
	return 0;
	}

	if (starts_with(var, "column."))
	return git_column_config(var, value, "tag", &colopts);
	return git_color_default_config(var, value, cb);
	}

	static void write_tag_body(int fd, const struct object_id *oid)
	{
	unsigned long size;
	enum object_type type;
	char buf, sp;

	buf = read_sha1_file(oid->hash, &type, &size);
	if (!buf)
	return;
	/* skip header */
	sp = strstr(buf, "\n\n");

	if (!sp \|\| !size \|\| type != OBJ_TAG) {
	free(buf);
	return;
	}
	sp += 2; /* skip the 2 LFs */
	write_or_die(fd, sp, parse_signature(sp, buf + size - sp));

	free(buf);
	}

	static int build_tag_object(struct strbuf buf, int sign, struct object_id result)
	{
	if (sign && do_sign(buf) < 0)
	return error(_("unable to sign the tag"));
	if (write_sha1_file(buf->buf, buf->len, tag_type, result->hash) < 0)
	return error(_("unable to write tag file"));
	return 0;
	}

	struct create_tag_options {
	unsigned int message_given:1;
	unsigned int sign;
	enum {
	CLEANUP_NONE,
	CLEANUP_SPACE,
	CLEANUP_ALL
	} cleanup_mode;
	};

	static void create_tag(const struct object_id object, const char tag,
	struct strbuf buf, struct create_tag_options opt,
	struct object_id prev, struct object_id result)
	{
	enum object_type type;
	struct strbuf header = STRBUF_INIT;
	char *path = NULL;

	type = sha1_object_info(object->hash, NULL);
	if (type <= OBJ_NONE)
	die(_("bad object type."));

	strbuf_addf(&header,
	"object %s\n"
	"type %s\n"
	"tag %s\n"
	"tagger %s\n\n",
	oid_to_hex(object),
	typename(type),
	tag,
	git_committer_info(IDENT_STRICT));

	if (!opt->message_given) {
	int fd;

	/* write the template message before editing: */
	path = git_pathdup("TAG_EDITMSG");
	fd = open(path, O_CREAT \| O_TRUNC \| O_WRONLY, 0600);
	if (fd < 0)
	die_errno(_("could not create file '%s'"), path);

	if (!is_null_oid(prev)) {
	write_tag_body(fd, prev);
	} else {
	struct strbuf buf = STRBUF_INIT;
	strbuf_addch(&buf, '\n');
	if (opt->cleanup_mode == CLEANUP_ALL)
	strbuf_commented_addf(&buf, _(tag_template), tag, comment_line_char);
	else
	strbuf_commented_addf(&buf, _(tag_template_nocleanup), tag, comment_line_char);
	write_or_die(fd, buf.buf, buf.len);
	strbuf_release(&buf);
	}
	close(fd);

	if (launch_editor(path, buf, NULL)) {
	fprintf(stderr,
	_("Please supply the message using either -m or -F option.\n"));
	exit(1);
	}
	}

	if (opt->cleanup_mode != CLEANUP_NONE)
	strbuf_stripspace(buf, opt->cleanup_mode == CLEANUP_ALL);

	if (!opt->message_given && !buf->len)
	die(_("no tag message?"));

	strbuf_insert(buf, 0, header.buf, header.len);
	strbuf_release(&header);

	if (build_tag_object(buf, opt->sign, result) < 0) {
	if (path)
	fprintf(stderr, _("The tag message has been left in %s\n"),
	path);
	exit(128);
	}
	if (path) {
	unlink_or_warn(path);
	free(path);
	}
	}

	static void create_reflog_msg(const struct object_id oid, struct strbuf sb)
	{
	enum object_type type;
	struct commit *c;
	char *buf;
	unsigned long size;
	int subject_len = 0;
	const char *subject_start;

	char *rla = getenv("GIT_REFLOG_ACTION");
	if (rla) {
	strbuf_addstr(sb, rla);
	} else {
	strbuf_addstr(sb, "tag: tagging ");
	strbuf_add_unique_abbrev(sb, oid->hash, DEFAULT_ABBREV);
	}

	strbuf_addstr(sb, " (");
	type = sha1_object_info(oid->hash, NULL);
	switch (type) {
	default:
	strbuf_addstr(sb, "object of unknown type");
	break;
	case OBJ_COMMIT:
	if ((buf = read_sha1_file(oid->hash, &type, &size)) != NULL) {
	subject_len = find_commit_subject(buf, &subject_start);
	strbuf_insert(sb, sb->len, subject_start, subject_len);
	} else {
	strbuf_addstr(sb, "commit object");
	}
	free(buf);

	if ((c = lookup_commit_reference(oid)) != NULL)
	strbuf_addf(sb, ", %s", show_date(c->date, 0, DATE_MODE(SHORT)));
	break;
	case OBJ_TREE:
	strbuf_addstr(sb, "tree object");
	break;
	case OBJ_BLOB:
	strbuf_addstr(sb, "blob object");
	break;
	case OBJ_TAG:
	strbuf_addstr(sb, "other tag object");
	break;
	}
	strbuf_addch(sb, ')');
	}

	struct msg_arg {
	int given;
	struct strbuf buf;
	};

	static int parse_msg_arg(const struct option opt, const char arg, int unset)
	{
	struct msg_arg *msg = opt->value;

	if (!arg)
	return -1;
	if (msg->buf.len)
	strbuf_addstr(&(msg->buf), "\n\n");
	strbuf_addstr(&(msg->buf), arg);
	msg->given = 1;
	return 0;
	}

	static int strbuf_check_tag_ref(struct strbuf sb, const char name)
	{
	if (name[0] == '-')
	return -1;

	strbuf_reset(sb);
	strbuf_addf(sb, "refs/tags/%s", name);

	return check_refname_format(sb->buf, 0);
	}

	int cmd_tag(int argc, const char *argv, const char prefix)
	{
	struct strbuf buf = STRBUF_INIT;
	struct strbuf ref = STRBUF_INIT;
	struct strbuf reflog_msg = STRBUF_INIT;
	struct object_id object, prev;
	const char object_ref, tag;
	struct create_tag_options opt;
	char *cleanup_arg = NULL;
	int create_reflog = 0;
	int annotate = 0, force = 0;
	int cmdmode = 0, create_tag_object = 0;
	const char msgfile = NULL, keyid = NULL;
	struct msg_arg msg = { 0, STRBUF_INIT };
	struct ref_transaction *transaction;
	struct strbuf err = STRBUF_INIT;
	struct ref_filter filter;
	static struct ref_sorting sorting = NULL, *sorting_tail = &sorting;
	struct ref_format format = REF_FORMAT_INIT;
	int icase = 0;
	struct option options[] = {
	OPT_CMDMODE('l', "list", &cmdmode, N_("list tag names"), 'l'),
	{ OPTION_INTEGER, 'n', NULL, &filter.lines, N_("n"),
	N_("print <n> lines of each tag message"),
	PARSE_OPT_OPTARG, NULL, 1 },
	OPT_CMDMODE('d', "delete", &cmdmode, N_("delete tags"), 'd'),
	OPT_CMDMODE('v', "verify", &cmdmode, N_("verify tags"), 'v'),

	OPT_GROUP(N_("Tag creation options")),
	OPT_BOOL('a', "annotate", &annotate,
	N_("annotated tag, needs a message")),
	OPT_CALLBACK('m', "message", &msg, N_("message"),
	N_("tag message"), parse_msg_arg),
	OPT_FILENAME('F', "file", &msgfile, N_("read message from file")),
	OPT_BOOL('s', "sign", &opt.sign, N_("annotated and GPG-signed tag")),
	OPT_STRING(0, "cleanup", &cleanup_arg, N_("mode"),
	N_("how to strip spaces and #comments from message")),
	OPT_STRING('u', "local-user", &keyid, N_("key-id"),
	N_("use another key to sign the tag")),
	OPT__FORCE(&force, N_("replace the tag if exists")),
	OPT_BOOL(0, "create-reflog", &create_reflog, N_("create a reflog")),

	OPT_GROUP(N_("Tag listing options")),
	OPT_COLUMN(0, "column", &colopts, N_("show tag list in columns")),
	OPT_CONTAINS(&filter.with_commit, N_("print only tags that contain the commit")),
	OPT_NO_CONTAINS(&filter.no_commit, N_("print only tags that don't contain the commit")),
	OPT_WITH(&filter.with_commit, N_("print only tags that contain the commit")),
	OPT_WITHOUT(&filter.no_commit, N_("print only tags that don't contain the commit")),
	OPT_MERGED(&filter, N_("print only tags that are merged")),
	OPT_NO_MERGED(&filter, N_("print only tags that are not merged")),
	OPT_CALLBACK(0 , "sort", sorting_tail, N_("key"),
	N_("field name to sort on"), &parse_opt_ref_sorting),
	{
	OPTION_CALLBACK, 0, "points-at", &filter.points_at, N_("object"),
	N_("print only tags of the object"), PARSE_OPT_LASTARG_DEFAULT,
	parse_opt_object_name, (intptr_t) "HEAD"
	},
	OPT_STRING( 0 , "format", &format.format, N_("format"),
	N_("format to use for the output")),
	OPT__COLOR(&format.use_color, N_("respect format colors")),
	OPT_BOOL('i', "ignore-case", &icase, N_("sorting and filtering are case insensitive")),
	OPT_END()
	};

	setup_ref_filter_porcelain_msg();

	git_config(git_tag_config, sorting_tail);

	memset(&opt, 0, sizeof(opt));
	memset(&filter, 0, sizeof(filter));
	filter.lines = -1;

	argc = parse_options(argc, argv, prefix, options, git_tag_usage, 0);

	if (keyid) {
	opt.sign = 1;
	set_signing_key(keyid);
	}
	create_tag_object = (opt.sign \|\| annotate \|\| msg.given \|\| msgfile);

	if (!cmdmode) {
	if (argc == 0)
	cmdmode = 'l';
	else if (filter.with_commit \|\| filter.no_commit \|\|
	filter.points_at.nr \|\| filter.merge_commit \|\|
	filter.lines != -1)
	cmdmode = 'l';
	}

	if (cmdmode == 'l')
	setup_auto_pager("tag", 1);

	if ((create_tag_object \|\| force) && (cmdmode != 0))
	usage_with_options(git_tag_usage, options);

	finalize_colopts(&colopts, -1);
	if (cmdmode == 'l' && filter.lines != -1) {
	if (explicitly_enable_column(colopts))
	die(_("--column and -n are incompatible"));
	colopts = 0;
	}
	if (!sorting)
	sorting = ref_default_sorting();
	sorting->ignore_case = icase;
	filter.ignore_case = icase;
	if (cmdmode == 'l') {
	int ret;
	if (column_active(colopts)) {
	struct column_options copts;
	memset(&copts, 0, sizeof(copts));
	copts.padding = 2;
	run_column_filter(colopts, &copts);
	}
	filter.name_patterns = argv;
	ret = list_tags(&filter, sorting, &format);
	if (column_active(colopts))
	stop_column_filter();
	return ret;
	}
	if (filter.lines != -1)
	die(_("-n option is only allowed in list mode"));
	if (filter.with_commit)
	die(_("--contains option is only allowed in list mode"));
	if (filter.no_commit)
	die(_("--no-contains option is only allowed in list mode"));
	if (filter.points_at.nr)
	die(_("--points-at option is only allowed in list mode"));
	if (filter.merge_commit)
	die(_("--merged and --no-merged options are only allowed in list mode"));
	if (cmdmode == 'd')
	return for_each_tag_name(argv, delete_tag, NULL);
	if (cmdmode == 'v') {
	if (format.format && verify_ref_format(&format))
	usage_with_options(git_tag_usage, options);
	return for_each_tag_name(argv, verify_tag, &format);
	}

	if (msg.given \|\| msgfile) {
	if (msg.given && msgfile)
	die(_("only one -F or -m option is allowed."));
	if (msg.given)
	strbuf_addbuf(&buf, &(msg.buf));
	else {
	if (!strcmp(msgfile, "-")) {
	if (strbuf_read(&buf, 0, 1024) < 0)
	die_errno(_("cannot read '%s'"), msgfile);
	} else {
	if (strbuf_read_file(&buf, msgfile, 1024) < 0)
	die_errno(_("could not open or read '%s'"),
	msgfile);
	}
	}
	}

	tag = argv[0];

	object_ref = argc == 2 ? argv[1] : "HEAD";
	if (argc > 2)
	die(_("too many params"));

	if (get_oid(object_ref, &object))
	die(_("Failed to resolve '%s' as a valid ref."), object_ref);

	if (strbuf_check_tag_ref(&ref, tag))
	die(_("'%s' is not a valid tag name."), tag);

	if (read_ref(ref.buf, prev.hash))
	oidclr(&prev);
	else if (!force)
	die(_("tag '%s' already exists"), tag);

	opt.message_given = msg.given \|\| msgfile;

	if (!cleanup_arg \|\| !strcmp(cleanup_arg, "strip"))
	opt.cleanup_mode = CLEANUP_ALL;
	else if (!strcmp(cleanup_arg, "verbatim"))
	opt.cleanup_mode = CLEANUP_NONE;
	else if (!strcmp(cleanup_arg, "whitespace"))
	opt.cleanup_mode = CLEANUP_SPACE;
	else
	die(_("Invalid cleanup mode %s"), cleanup_arg);

	create_reflog_msg(&object, &reflog_msg);

	if (create_tag_object) {
	if (force_sign_annotate && !annotate)
	opt.sign = 1;
	create_tag(&object, tag, &buf, &opt, &prev, &object);
	}

	transaction = ref_transaction_begin(&err);
	if (!transaction \|\|
	ref_transaction_update(transaction, ref.buf, object.hash, prev.hash,
	create_reflog ? REF_FORCE_CREATE_REFLOG : 0,
	reflog_msg.buf, &err) \|\|
	ref_transaction_commit(transaction, &err))
	die("%s", err.buf);
	ref_transaction_free(transaction);
	if (force && !is_null_oid(&prev) && oidcmp(&prev, &object))
	printf(_("Updated tag '%s' (was %s)\n"), tag, find_unique_abbrev(prev.hash, DEFAULT_ABBREV));

	strbuf_release(&err);
	strbuf_release(&buf);
	strbuf_release(&ref);
	strbuf_release(&reflog_msg);
	return 0;
	}