int run_add_interactive(const char *revision, const char *patch_mode,
			const struct pathspec *pathspec)
{
	int status, i;
	struct argv_array argv = ARGV_ARRAY_INIT;

	argv_array_push(&argv, "add--interactive");
	if (patch_mode)
		argv_array_push(&argv, patch_mode);
	if (revision)
		argv_array_push(&argv, revision);
	argv_array_push(&argv, "--");
	for (i = 0; i < pathspec->nr; i++)
		/* pass original pathspec, to be re-parsed */
		argv_array_push(&argv, pathspec->items[i].original);

	status = run_command_v_opt(argv.argv, RUN_GIT_CMD);
	argv_array_clear(&argv);
	return status;
}

/**
 * Given the current HEAD SHA1, the merge head returned from git-fetch and the
 * fork point calculated by get_rebase_fork_point(), runs git-rebase with the
 * appropriate arguments and returns its exit status.
 */
static int run_rebase(const unsigned char *curr_head,
		const unsigned char *merge_head,
		const unsigned char *fork_point)
{
	int ret;
	unsigned char oct_merge_base[GIT_SHA1_RAWSZ];
	struct argv_array args = ARGV_ARRAY_INIT;

	if (!get_octopus_merge_base(oct_merge_base, curr_head, merge_head, fork_point))
		if (!is_null_sha1(fork_point) && !hashcmp(oct_merge_base, fork_point))
			fork_point = NULL;

	argv_array_push(&args, "rebase");

	/* Shared options */
	argv_push_verbosity(&args);

	/* Options passed to git-rebase */
	if (opt_rebase == REBASE_PRESERVE)
		argv_array_push(&args, "--preserve-merges");
	else if (opt_rebase == REBASE_INTERACTIVE)
		argv_array_push(&args, "--interactive");
	if (opt_diffstat)
		argv_array_push(&args, opt_diffstat);
	argv_array_pushv(&args, opt_strategies.argv);
	argv_array_pushv(&args, opt_strategy_opts.argv);
	if (opt_gpg_sign)
		argv_array_push(&args, opt_gpg_sign);

	argv_array_push(&args, "--onto");
	argv_array_push(&args, sha1_to_hex(merge_head));

	if (fork_point && !is_null_sha1(fork_point))
		argv_array_push(&args, sha1_to_hex(fork_point));
	else
		argv_array_push(&args, sha1_to_hex(merge_head));

	ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
	argv_array_clear(&args);
	return ret;
}

/**
 * Runs git-merge, returning its exit status.
 */
static int run_merge(void)
{
	int ret;
	struct argv_array args = ARGV_ARRAY_INIT;

	argv_array_pushl(&args, "merge", NULL);

	/* Shared options */
	argv_push_verbosity(&args);
	if (opt_progress)
		argv_array_push(&args, opt_progress);

	/* Options passed to git-merge */
	if (opt_diffstat)
		argv_array_push(&args, opt_diffstat);
	if (opt_log)
		argv_array_push(&args, opt_log);
	if (opt_signoff)
		argv_array_push(&args, opt_signoff);
	if (opt_squash)
		argv_array_push(&args, opt_squash);
	if (opt_commit)
		argv_array_push(&args, opt_commit);
	if (opt_edit)
		argv_array_push(&args, opt_edit);
	if (opt_ff)
		argv_array_push(&args, opt_ff);
	if (opt_verify_signatures)
		argv_array_push(&args, opt_verify_signatures);
	argv_array_pushv(&args, opt_strategies.argv);
	argv_array_pushv(&args, opt_strategy_opts.argv);
	if (opt_gpg_sign)
		argv_array_push(&args, opt_gpg_sign);
	if (opt_allow_unrelated_histories > 0)
		argv_array_push(&args, "--allow-unrelated-histories");

	argv_array_push(&args, "FETCH_HEAD");
	ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
	argv_array_clear(&args);
	return ret;
}

static int push_dav(int nr_spec, char **specs)
{
	const char **argv = xmalloc((10 + nr_spec) * sizeof(char*));
	int argc = 0, i;

	argv[argc++] = "http-push";
	argv[argc++] = "--helper-status";
	if (options.dry_run)
		argv[argc++] = "--dry-run";
	if (options.verbosity > 1)
		argv[argc++] = "--verbose";
	argv[argc++] = url;
	for (i = 0; i < nr_spec; i++)
		argv[argc++] = specs[i];
	argv[argc++] = NULL;

	if (run_command_v_opt(argv, RUN_GIT_CMD))
		die("git-%s failed", argv[0]);
	free(argv);
	return 0;
}

static void restore_state(void)
{
	struct strbuf sb = STRBUF_INIT;
	const char *args[] = { "stash", "apply", NULL, NULL };

	if (is_null_sha1(stash))
		return;

	reset_hard(head, 1);

	args[2] = sha1_to_hex(stash);

	/*
	 * It is OK to ignore error here, for example when there was
	 * nothing to restore.
	 */
	run_command_v_opt(args, RUN_GIT_CMD);

	strbuf_release(&sb);
	refresh_cache(REFRESH_QUIET);
}

int run_add_interactive(const char *revision, const char *patch_mode,
			const struct pathspec *pathspec)
{
	int status, ac, i;
	const char **args;

	args = xcalloc(sizeof(const char *), (pathspec->nr + 6));
	ac = 0;
	args[ac++] = "add--interactive";
	if (patch_mode)
		args[ac++] = patch_mode;
	if (revision)
		args[ac++] = revision;
	args[ac++] = "--";
	for (i = 0; i < pathspec->nr; i++)
		/* pass original pathspec, to be re-parsed */
		args[ac++] = pathspec->items[i].original;

	status = run_command_v_opt(args, RUN_GIT_CMD);
	free(args);
	return status;
}

static int curl_transport_push(struct transport *transport, int refspec_nr, const char **refspec, int flags)
{
	const char **argv;
	int argc;
	int err;

	if (flags & TRANSPORT_PUSH_MIRROR)
		return error("http transport does not support mirror mode");

	argv = xmalloc((refspec_nr + 12) * sizeof(char *));
	argv[0] = "http-push";
	argc = 1;
	if (flags & TRANSPORT_PUSH_ALL)
		argv[argc++] = "--all";
	if (flags & TRANSPORT_PUSH_FORCE)
		argv[argc++] = "--force";
	if (flags & TRANSPORT_PUSH_DRY_RUN)
		argv[argc++] = "--dry-run";
	if (flags & TRANSPORT_PUSH_VERBOSE)
		argv[argc++] = "--verbose";
	argv[argc++] = transport->url;
	while (refspec_nr--)
		argv[argc++] = *refspec++;
	argv[argc] = NULL;
	err = run_command_v_opt(argv, RUN_GIT_CMD);
	switch (err) {
	case -ERR_RUN_COMMAND_FORK:
		error("unable to fork for %s", argv[0]);
	case -ERR_RUN_COMMAND_EXEC:
		error("unable to exec %s", argv[0]);
		break;
	case -ERR_RUN_COMMAND_WAITPID:
	case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
	case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
	case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
		error("%s died with strange error", argv[0]);
	}
	return !!err;
}

static void execv_dashed_external(const char **argv)
{
	struct strbuf cmd = STRBUF_INIT;
	const char *tmp;
	int status;

	if (get_super_prefix())
		die("%s doesn't support --super-prefix", argv[0]);

	if (use_pager == -1)
		use_pager = check_pager_config(argv[0]);
	commit_pager_choice();

	strbuf_addf(&cmd, "git-%s", argv[0]);

	/*
	 * argv[0] must be the git command, but the argv array
	 * belongs to the caller, and may be reused in
	 * subsequent loop iterations. Save argv[0] and
	 * restore it on error.
	 */
	tmp = argv[0];
	argv[0] = cmd.buf;

	trace_argv_printf(argv, "trace: exec:");

	/*
	 * if we fail because the command is not found, it is
	 * OK to return. Otherwise, we just pass along the status code.
	 */
	status = run_command_v_opt(argv, RUN_SILENT_EXEC_FAILURE | RUN_CLEAN_ON_EXIT);
	if (status >= 0 || errno != ENOENT)
		exit(status);

	argv[0] = tmp;

	strbuf_release(&cmd);
}

static void execv_dashed_external(const char **argv)
{
	struct strbuf cmd = STRBUF_INIT;
	const char *tmp;
	int status;

	strbuf_addf(&cmd, "perf-%s", argv[0]);

	tmp = argv[0];
	argv[0] = cmd.buf;

	status = run_command_v_opt(argv, 0);
	if (status != -ERR_RUN_COMMAND_EXEC) {
		if (IS_RUN_COMMAND_ERR(status))
			die("unable to run '%s'", argv[0]);
		exit(-status);
	}
	errno = ENOENT; 

	argv[0] = tmp;

	strbuf_release(&cmd);
}

static int sequencer_skip(struct replay_opts *opts)
{
	const char *argv[3]; /* reset --hard + NULL */
	struct string_list merge_rr = STRING_LIST_INIT_DUP;
	int ret;

	if (setup_rerere(&merge_rr, 0) >= 0) {
		rerere_clear(&merge_rr);
		string_list_clear(&merge_rr, 1);
	}

	argv[0] = "reset";
	argv[1] = "--hard";
	argv[2] = NULL;
	ret = run_command_v_opt(argv, RUN_GIT_CMD);
	if (ret)
		return ret;

	discard_cache();
	read_cache();

	return sequencer_continue(opts, 1);
}

static void execv_dashed_external(const char **argv)
{
	char *cmd;
	const char *tmp;
	int status;

	if (asprintf(&cmd, "perf-%s", argv[0]) < 0)
		goto do_die;

	/*
	 * argv[0] must be the perf command, but the argv array
	 * belongs to the caller, and may be reused in
	 * subsequent loop iterations. Save argv[0] and
	 * restore it on error.
	 */
	tmp = argv[0];
	argv[0] = cmd;

	/*
	 * if we fail because the command is not found, it is
	 * OK to return. Otherwise, we just pass along the status code.
	 */
	status = run_command_v_opt(argv, 0);
	if (status != -ERR_RUN_COMMAND_EXEC) {
		if (IS_RUN_COMMAND_ERR(status)) {
do_die:
			pr_err("FATAL: unable to run '%s'", argv[0]);
			status = -128;
		}
		exit(-status);
	}
	errno = ENOENT; /* as if we called execvp */

	argv[0] = tmp;
	zfree(&cmd);
}

static int merge_entry(int pos, const char *path)
{
	int found;
	const char *arguments[] = { pgm, "", "", "", path, "", "", "", NULL };
	char hexbuf[4][GIT_SHA1_HEXSZ + 1];
	char ownbuf[4][60];

	if (pos >= active_nr)
		die("git merge-index: %s not in the cache", path);
	found = 0;
	do {
		const struct cache_entry *ce = active_cache[pos];
		int stage = ce_stage(ce);

		if (strcmp(ce->name, path))
			break;
		found++;
		oid_to_hex_r(hexbuf[stage], &ce->oid);
		xsnprintf(ownbuf[stage], sizeof(ownbuf[stage]), "%o", ce->ce_mode);
		arguments[stage] = hexbuf[stage];
		arguments[stage + 4] = ownbuf[stage];
	} while (++pos < active_nr);
	if (!found)
		die("git merge-index: %s not in the cache", path);

	if (run_command_v_opt(arguments, 0)) {
		if (one_shot)
			err++;
		else {
			if (!quiet)
				die("merge program failed");
			exit(1);
		}
	}
	return found;
}

static int reset_index_file(const unsigned char *sha1, int reset_type, int quiet)
{
	int i = 0;
	const char *args[6];

	args[i++] = "read-tree";
	if (!quiet)
		args[i++] = "-v";
	switch (reset_type) {
	case MERGE:
		args[i++] = "-u";
		args[i++] = "-m";
		break;
	case HARD:
		args[i++] = "-u";
		/* fallthrough */
	default:
		args[i++] = "--reset";
	}
	args[i++] = sha1_to_hex(sha1);
	args[i] = NULL;

	return run_command_v_opt(args, RUN_GIT_CMD);
}

/*
 * 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.
 */
static int run_git_commit(const char *defmsg, struct replay_opts *opts,
			  int allow_empty)
{
	struct argv_array array;
	int rc;
	char *gpg_sign;

	argv_array_init(&array);
	argv_array_push(&array, "commit");
	argv_array_push(&array, "-n");
	if (opts->quiet)
		argv_array_push(&array, "-q");

	if (opts->gpg_sign) {
		gpg_sign = xmalloc(3 + strlen(opts->gpg_sign));
		sprintf(gpg_sign, "-S%s", opts->gpg_sign);
		argv_array_push(&array, gpg_sign);
		free(gpg_sign);
	}
	if (opts->signoff)
		argv_array_push(&array, "-s");
	if (!opts->edit) {
		argv_array_push(&array, "-F");
		argv_array_push(&array, defmsg);
	}

	if (allow_empty)
		argv_array_push(&array, "--allow-empty");

	if (opts->allow_empty_message)
		argv_array_push(&array, "--allow-empty-message");

	rc = run_command_v_opt(array.argv, RUN_GIT_CMD);
	argv_array_clear(&array);
	return rc;
}

int cmd_gc(int argc, const char **argv, const char *prefix)
{
	int aggressive = 0;
	int auto_gc = 0;
	int quiet = 0;
	int force = 0;
	const char *name;
	pid_t pid;

	struct option builtin_gc_options[] = {
		OPT__QUIET(&quiet, N_("suppress progress reporting")),
		{ OPTION_STRING, 0, "prune", &prune_expire, N_("date"),
			N_("prune unreferenced objects"),
			PARSE_OPT_OPTARG, NULL, (intptr_t)prune_expire },
		OPT_BOOL(0, "aggressive", &aggressive, N_("be more thorough (increased runtime)")),
		OPT_BOOL(0, "auto", &auto_gc, N_("enable auto-gc mode")),
		OPT_BOOL(0, "force", &force, N_("force running gc even if there may be another gc running")),
		OPT_END()
	};

	if (argc == 2 && !strcmp(argv[1], "-h"))
		usage_with_options(builtin_gc_usage, builtin_gc_options);

	argv_array_pushl(&pack_refs_cmd, "pack-refs", "--all", "--prune", NULL);
	argv_array_pushl(&reflog, "reflog", "expire", "--all", NULL);
	argv_array_pushl(&repack, "repack", "-d", "-l", NULL);
	argv_array_pushl(&prune, "prune", "--expire", NULL );
	argv_array_pushl(&rerere, "rerere", "gc", NULL);

	git_config(gc_config, NULL);

	if (pack_refs < 0)
		pack_refs = !is_bare_repository();

	argc = parse_options(argc, argv, prefix, builtin_gc_options,
			     builtin_gc_usage, 0);
	if (argc > 0)
		usage_with_options(builtin_gc_usage, builtin_gc_options);

	if (aggressive) {
		argv_array_push(&repack, "-f");
		argv_array_push(&repack, "--depth=250");
		if (aggressive_window > 0)
			argv_array_pushf(&repack, "--window=%d", aggressive_window);
	}
	if (quiet)
		argv_array_push(&repack, "-q");

	if (auto_gc) {
		/*
		 * Auto-gc should be least intrusive as possible.
		 */
		if (!need_to_gc())
			return 0;
		if (!quiet)
			fprintf(stderr,
					_("Auto packing the repository for optimum performance. You may also\n"
					"run \"git gc\" manually. See "
					"\"git help gc\" for more information.\n"));
	} else
		add_repack_all_option();

	name = lock_repo_for_gc(force, &pid);
	if (name) {
		if (auto_gc)
			return 0; /* be quiet on --auto */
		die(_("gc is already running on machine '%s' pid %"PRIuMAX" (use --force if not)"),
		    name, (uintmax_t)pid);
	}

	if (pack_refs && run_command_v_opt(pack_refs_cmd.argv, RUN_GIT_CMD))
		return error(FAILED_RUN, pack_refs_cmd.argv[0]);

	if (run_command_v_opt(reflog.argv, RUN_GIT_CMD))
		return error(FAILED_RUN, reflog.argv[0]);

	if (run_command_v_opt(repack.argv, RUN_GIT_CMD))
		return error(FAILED_RUN, repack.argv[0]);

	if (prune_expire) {
		argv_array_push(&prune, prune_expire);
		if (quiet)
			argv_array_push(&prune, "--no-progress");
		if (run_command_v_opt(prune.argv, RUN_GIT_CMD))
			return error(FAILED_RUN, prune.argv[0]);
	}

	if (run_command_v_opt(rerere.argv, RUN_GIT_CMD))
		return error(FAILED_RUN, rerere.argv[0]);

	if (auto_gc && too_many_loose_objects())
		warning(_("There are too many unreachable loose objects; "
			"run 'git prune' to remove them."));

	return 0;
}

static const char *unpack(void)
{
	struct pack_header hdr;
	const char *hdr_err;
	char hdr_arg[38];

	hdr_err = parse_pack_header(&hdr);
	if (hdr_err)
		return hdr_err;
	snprintf(hdr_arg, sizeof(hdr_arg),
			"--pack_header=%"PRIu32",%"PRIu32,
			ntohl(hdr.hdr_version), ntohl(hdr.hdr_entries));

	if (ntohl(hdr.hdr_entries) < unpack_limit) {
		int code, i = 0;
		const char *unpacker[4];
		unpacker[i++] = "unpack-objects";
		if (receive_fsck_objects)
			unpacker[i++] = "--strict";
		unpacker[i++] = hdr_arg;
		unpacker[i++] = NULL;
		code = run_command_v_opt(unpacker, RUN_GIT_CMD);
		switch (code) {
		case 0:
			return NULL;
		case -ERR_RUN_COMMAND_FORK:
			return "unpack fork failed";
		case -ERR_RUN_COMMAND_EXEC:
			return "unpack execute failed";
		case -ERR_RUN_COMMAND_WAITPID:
			return "waitpid failed";
		case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
			return "waitpid is confused";
		case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
			return "unpacker died of signal";
		case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
			return "unpacker died strangely";
		default:
			return "unpacker exited with error code";
		}
	} else {
		const char *keeper[7];
		int s, status, i = 0;
		char keep_arg[256];
		struct child_process ip;

		s = sprintf(keep_arg, "--keep=receive-pack %"PRIuMAX" on ", (uintmax_t) getpid());
		if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
			strcpy(keep_arg + s, "localhost");

		keeper[i++] = "index-pack";
		keeper[i++] = "--stdin";
		if (receive_fsck_objects)
			keeper[i++] = "--strict";
		keeper[i++] = "--fix-thin";
		keeper[i++] = hdr_arg;
		keeper[i++] = keep_arg;
		keeper[i++] = NULL;
		memset(&ip, 0, sizeof(ip));
		ip.argv = keeper;
		ip.out = -1;
		ip.git_cmd = 1;
		if (start_command(&ip))
			return "index-pack fork failed";
		pack_lockfile = index_pack_lockfile(ip.out);
		close(ip.out);
		status = finish_command(&ip);
		if (!status) {
			reprepare_packed_git();
			return NULL;
		}
		return "index-pack abnormal exit";
	}
}

static int handle_alias(int *argcp, const char ***argv)
{
	int envchanged = 0, ret = 0, saved_errno = errno;
	const char *subdir;
	int count, option_count;
	const char **new_argv;
	const char *alias_command;
	char *alias_string;
	int unused_nongit;

	subdir = setup_git_directory_gently(&unused_nongit);

	alias_command = (*argv)[0];
	alias_string = alias_lookup(alias_command);
	if (alias_string) {
		if (alias_string[0] == '!') {
			const char **alias_argv;
			int argc = *argcp, i;

			commit_pager_choice();

			/* build alias_argv */
			alias_argv = xmalloc(sizeof(*alias_argv) * (argc + 1));
			alias_argv[0] = alias_string + 1;
			for (i = 1; i < argc; ++i)
				alias_argv[i] = (*argv)[i];
			alias_argv[argc] = NULL;

			ret = run_command_v_opt(alias_argv, RUN_USING_SHELL);
			if (ret >= 0)   /* normal exit */
				exit(ret);

			die_errno("While expanding alias '%s': '%s'",
			    alias_command, alias_string + 1);
		}
		count = split_cmdline(alias_string, &new_argv);
		if (count < 0)
			die("Bad alias.%s string: %s", alias_command,
			    split_cmdline_strerror(count));
		option_count = handle_options(&new_argv, &count, &envchanged);
		if (envchanged)
			die("alias '%s' changes environment variables\n"
				 "You can use '!git' in the alias to do this.",
				 alias_command);
		memmove(new_argv - option_count, new_argv,
				count * sizeof(char *));
		new_argv -= option_count;

		if (count < 1)
			die("empty alias for %s", alias_command);

		if (!strcmp(alias_command, new_argv[0]))
			die("recursive alias: %s", alias_command);

		trace_argv_printf(new_argv,
				  "trace: alias expansion: %s =>",
				  alias_command);

		new_argv = xrealloc(new_argv, sizeof(char *) *
				    (count + *argcp));
		/* insert after command name */
		memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);

		*argv = new_argv;
		*argcp += count - 1;

		ret = 1;
	}

	if (subdir && chdir(subdir))
		die_errno("Cannot change to '%s'", subdir);

	errno = saved_errno;

	return ret;
}

int cmd_gc(int argc, const char **argv, const char *prefix)
{
	int aggressive = 0;
	int auto_gc = 0;
	int quiet = 0;
	char buf[80];

	struct option builtin_gc_options[] = {
		OPT__QUIET(&quiet, "suppress progress reporting"),
		{ OPTION_STRING, 0, "prune", &prune_expire, "date",
			"prune unreferenced objects",
			PARSE_OPT_OPTARG, NULL, (intptr_t)prune_expire },
		OPT_BOOLEAN(0, "aggressive", &aggressive, "be more thorough (increased runtime)"),
		OPT_BOOLEAN(0, "auto", &auto_gc, "enable auto-gc mode"),
		OPT_END()
	};

	if (argc == 2 && !strcmp(argv[1], "-h"))
		usage_with_options(builtin_gc_usage, builtin_gc_options);

	git_config(gc_config, NULL);

	if (pack_refs < 0)
		pack_refs = !is_bare_repository();

	argc = parse_options(argc, argv, prefix, builtin_gc_options,
			     builtin_gc_usage, 0);
	if (argc > 0)
		usage_with_options(builtin_gc_usage, builtin_gc_options);

	if (aggressive) {
		append_option(argv_repack, "-f", MAX_ADD);
		append_option(argv_repack, "--depth=250", MAX_ADD);
		if (aggressive_window > 0) {
			sprintf(buf, "--window=%d", aggressive_window);
			append_option(argv_repack, buf, MAX_ADD);
		}
	}
	if (quiet)
		append_option(argv_repack, "-q", MAX_ADD);

	if (auto_gc) {
		/*
		 * Auto-gc should be least intrusive as possible.
		 */
		if (!need_to_gc())
			return 0;
		fprintf(stderr,
			"Auto packing the repository for optimum performance.%s\n",
			quiet
			? ""
			: (" You may also\n"
			   "run \"git gc\" manually. See "
			   "\"git help gc\" for more information."));
	} else
		append_option(argv_repack,
			      prune_expire && !strcmp(prune_expire, "now")
			      ? "-a" : "-A",
			      MAX_ADD);

	if (pack_refs && run_command_v_opt(argv_pack_refs, RUN_GIT_CMD))
		return error(FAILED_RUN, argv_pack_refs[0]);

	if (run_command_v_opt(argv_reflog, RUN_GIT_CMD))
		return error(FAILED_RUN, argv_reflog[0]);

	if (run_command_v_opt(argv_repack, RUN_GIT_CMD))
		return error(FAILED_RUN, argv_repack[0]);

	if (prune_expire) {
		argv_prune[2] = prune_expire;
		if (run_command_v_opt(argv_prune, RUN_GIT_CMD))
			return error(FAILED_RUN, argv_prune[0]);
	}

	if (run_command_v_opt(argv_rerere, RUN_GIT_CMD))
		return error(FAILED_RUN, argv_rerere[0]);

	if (auto_gc && too_many_loose_objects())
		warning("There are too many unreachable loose objects; "
			"run 'git prune' to remove them.");

	return 0;
}

//.........这里部分代码省略.........

	if (pack_refs < 0)
		pack_refs = !is_bare_repository();

	argc = parse_options(argc, argv, prefix, builtin_gc_options,
			     builtin_gc_usage, 0);
	if (argc > 0)
		usage_with_options(builtin_gc_usage, builtin_gc_options);

	if (aggressive) {
		argv_array_push(&repack, "-f");
		if (aggressive_depth > 0)
			argv_array_pushf(&repack, "--depth=%d", aggressive_depth);
		if (aggressive_window > 0)
			argv_array_pushf(&repack, "--window=%d", aggressive_window);
	}
	if (quiet)
		argv_array_push(&repack, "-q");

	if (auto_gc) {
		/*
		 * Auto-gc should be least intrusive as possible.
		 */
		if (!need_to_gc())
			return 0;
		if (!quiet) {
			if (detach_auto)
				fprintf(stderr, _("Auto packing the repository in background for optimum performance.\n"));
			else
				fprintf(stderr, _("Auto packing the repository for optimum performance.\n"));
			fprintf(stderr, _("See \"git help gc\" for manual housekeeping.\n"));
		}
		if (detach_auto) {
			if (report_last_gc_error())
				return -1;

			if (gc_before_repack())
				return -1;
			/*
			 * failure to daemonize is ok, we'll continue
			 * in foreground
			 */
			daemonized = !daemonize();
		}
	} else
		add_repack_all_option();

	name = lock_repo_for_gc(force, &pid);
	if (name) {
		if (auto_gc)
			return 0; /* be quiet on --auto */
		die(_("gc is already running on machine '%s' pid %"PRIuMAX" (use --force if not)"),
		    name, (uintmax_t)pid);
	}

	if (daemonized) {
		hold_lock_file_for_update(&log_lock,
					  git_path("gc.log"),
					  LOCK_DIE_ON_ERROR);
		dup2(get_lock_file_fd(&log_lock), 2);
		sigchain_push_common(process_log_file_on_signal);
		atexit(process_log_file_at_exit);
	}

	if (gc_before_repack())
		return -1;

	if (!repository_format_precious_objects) {
		if (run_command_v_opt(repack.argv, RUN_GIT_CMD))
			return error(FAILED_RUN, repack.argv[0]);

		if (prune_expire) {
			argv_array_push(&prune, prune_expire);
			if (quiet)
				argv_array_push(&prune, "--no-progress");
			if (run_command_v_opt(prune.argv, RUN_GIT_CMD))
				return error(FAILED_RUN, prune.argv[0]);
		}
	}

	if (prune_worktrees_expire) {
		argv_array_push(&prune_worktrees, prune_worktrees_expire);
		if (run_command_v_opt(prune_worktrees.argv, RUN_GIT_CMD))
			return error(FAILED_RUN, prune_worktrees.argv[0]);
	}

	if (run_command_v_opt(rerere.argv, RUN_GIT_CMD))
		return error(FAILED_RUN, rerere.argv[0]);

	report_garbage = report_pack_garbage;
	reprepare_packed_git();
	if (pack_garbage.nr > 0)
		clean_pack_garbage();

	if (auto_gc && too_many_loose_objects())
		warning(_("There are too many unreachable loose objects; "
			"run 'git prune' to remove them."));

	return 0;
}

//.........这里部分代码省略.........
				fprintf(stderr, _("Auto packing the repository for optimum performance.\n"));
			fprintf(stderr, _("See \"git help gc\" for manual housekeeping.\n"));
		}
		if (detach_auto) {
			int ret = report_last_gc_error();
			if (ret < 0)
				/* an I/O error occured, already reported */
				exit(128);
			if (ret == 1)
				/* Last gc --auto failed. Skip this one. */
				return 0;

			if (lock_repo_for_gc(force, &pid))
				return 0;
			gc_before_repack(); /* dies on failure */
			delete_tempfile(&pidfile);

			/*
			 * failure to daemonize is ok, we'll continue
			 * in foreground
			 */
			daemonized = !daemonize();
		}
	} else {
		struct string_list keep_pack = STRING_LIST_INIT_NODUP;

		if (keep_base_pack != -1) {
			if (keep_base_pack)
				find_base_packs(&keep_pack, 0);
		} else if (big_pack_threshold) {
			find_base_packs(&keep_pack, big_pack_threshold);
		}

		add_repack_all_option(&keep_pack);
		string_list_clear(&keep_pack, 0);
	}

	name = lock_repo_for_gc(force, &pid);
	if (name) {
		if (auto_gc)
			return 0; /* be quiet on --auto */
		die(_("gc is already running on machine '%s' pid %"PRIuMAX" (use --force if not)"),
		    name, (uintmax_t)pid);
	}

	if (daemonized) {
		hold_lock_file_for_update(&log_lock,
					  git_path("gc.log"),
					  LOCK_DIE_ON_ERROR);
		dup2(get_lock_file_fd(&log_lock), 2);
		sigchain_push_common(process_log_file_on_signal);
		atexit(process_log_file_at_exit);
	}

	gc_before_repack();

	if (!repository_format_precious_objects) {
		close_all_packs(the_repository->objects);
		if (run_command_v_opt(repack.argv, RUN_GIT_CMD))
			die(FAILED_RUN, repack.argv[0]);

		if (prune_expire) {
			argv_array_push(&prune, prune_expire);
			if (quiet)
				argv_array_push(&prune, "--no-progress");
			if (repository_format_partial_clone)
				argv_array_push(&prune,
						"--exclude-promisor-objects");
			if (run_command_v_opt(prune.argv, RUN_GIT_CMD))
				die(FAILED_RUN, prune.argv[0]);
		}
	}

	if (prune_worktrees_expire) {
		argv_array_push(&prune_worktrees, prune_worktrees_expire);
		if (run_command_v_opt(prune_worktrees.argv, RUN_GIT_CMD))
			die(FAILED_RUN, prune_worktrees.argv[0]);
	}

	if (run_command_v_opt(rerere.argv, RUN_GIT_CMD))
		die(FAILED_RUN, rerere.argv[0]);

	report_garbage = report_pack_garbage;
	reprepare_packed_git(the_repository);
	if (pack_garbage.nr > 0)
		clean_pack_garbage();

	if (gc_write_commit_graph)
		write_commit_graph_reachable(get_object_directory(), 0,
					     !quiet && !daemonized);

	if (auto_gc && too_many_loose_objects())
		warning(_("There are too many unreachable loose objects; "
			"run 'git prune' to remove them."));

	if (!daemonized)
		unlink(git_path("gc.log"));

	return 0;
}