Exemplo n.º 1
0
Arquivo: pull.c Projeto: 136357477/git
/**
 * Derives the remote tracking branch from the remote and refspec.
 *
 * FIXME: The current implementation assumes the default mapping of
 * refs/heads/<branch_name> to refs/remotes/<remote_name>/<branch_name>.
 */
static const char *get_tracking_branch(const char *remote, const char *refspec)
{
	struct refspec *spec;
	const char *spec_src;
	const char *merge_branch;

	spec = parse_fetch_refspec(1, &refspec);
	spec_src = spec->src;
	if (!*spec_src || !strcmp(spec_src, "HEAD"))
		spec_src = "HEAD";
	else if (skip_prefix(spec_src, "heads/", &spec_src))
		;
	else if (skip_prefix(spec_src, "refs/heads/", &spec_src))
		;
	else if (starts_with(spec_src, "refs/") ||
		starts_with(spec_src, "tags/") ||
		starts_with(spec_src, "remotes/"))
		spec_src = "";

	if (*spec_src) {
		if (!strcmp(remote, "."))
			merge_branch = mkpath("refs/heads/%s", spec_src);
		else
			merge_branch = mkpath("refs/remotes/%s/%s", remote, spec_src);
	} else
		merge_branch = NULL;

	free_refspec(1, spec);
	return merge_branch;
}
Exemplo n.º 2
0
Arquivo: fetch.c Projeto: davvid/git
static int fetch_one(struct remote *remote, int argc, const char **argv)
{
	int i;
	static const char **refs = NULL;
	int ref_nr = 0;
	int exit_code;

	if (!remote)
		die("Where do you want to fetch from today?");

	transport = transport_get(remote, NULL);
	transport_set_verbosity(transport, verbosity, progress);
	if (upload_pack)
		set_option(TRANS_OPT_UPLOADPACK, upload_pack);
	if (keep)
		set_option(TRANS_OPT_KEEP, "yes");
	if (depth)
		set_option(TRANS_OPT_DEPTH, depth);

	if (argc > 0) {
		int j = 0;
		refs = xcalloc(argc + 1, sizeof(const char *));
		for (i = 0; i < argc; i++) {
			if (!strcmp(argv[i], "tag")) {
				char *ref;
				i++;
				if (i >= argc)
					die("You need to specify a tag name.");
				ref = xmalloc(strlen(argv[i]) * 2 + 22);
				strcpy(ref, "refs/tags/");
				strcat(ref, argv[i]);
				strcat(ref, ":refs/tags/");
				strcat(ref, argv[i]);
				refs[j++] = ref;
			} else
				refs[j++] = argv[i];
		}
		refs[j] = NULL;
		ref_nr = j;
	}

	sigchain_push_common(unlock_pack_on_signal);
	atexit(unlock_pack);
	exit_code = do_fetch(transport,
			parse_fetch_refspec(ref_nr, refs), ref_nr);
	transport_disconnect(transport);
	transport = NULL;
	return exit_code;
}
Exemplo n.º 3
0
Arquivo: remote.c Projeto: certik/git
int for_each_remote(each_remote_fn fn, void *priv)
{
	int i, result = 0;
	read_config();
	for (i = 0; i < remotes_nr && !result; i++) {
		struct remote *r = remotes[i];
		if (!r)
			continue;
		if (!r->fetch)
			r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
						       r->fetch_refspec);
		if (!r->push)
			r->push = parse_push_refspec(r->push_refspec_nr,
						     r->push_refspec);
		result = fn(r, priv);
	}
	return result;
}
Exemplo n.º 4
0
Arquivo: remote.c Projeto: certik/git
struct remote *remote_get(const char *name)
{
	struct remote *ret;

	read_config();
	if (!name)
		name = default_remote_name;
	ret = make_remote(name, 0);
	if (valid_remote_nick(name)) {
		if (!ret->url)
			read_remotes_file(ret);
		if (!ret->url)
			read_branches_file(ret);
	}
	if (!ret->url)
		add_url_alias(ret, name);
	if (!ret->url)
		return NULL;
	ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
	ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
	return ret;
}
Exemplo n.º 5
0
int cmd_clone(int argc, const char **argv, const char *prefix)
{
	int is_bundle = 0, is_local;
	struct stat buf;
	const char *repo_name, *repo, *work_tree, *git_dir;
	char *path, *dir;
	int dest_exists;
	const struct ref *refs, *remote_head;
	const struct ref *remote_head_points_at;
	const struct ref *our_head_points_at;
	struct ref *mapped_refs;
	const struct ref *ref;
	struct strbuf key = STRBUF_INIT, value = STRBUF_INIT;
	struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
	struct transport *transport = NULL;
	const char *src_ref_prefix = "refs/heads/";
	struct remote *remote;
	int err = 0, complete_refs_before_fetch = 1;

	struct refspec *refspec;
	const char *fetch_pattern;

	packet_trace_identity("clone");
	argc = parse_options(argc, argv, prefix, builtin_clone_options,
			     builtin_clone_usage, 0);

	if (argc > 2)
		usage_msg_opt(_("Too many arguments."),
			builtin_clone_usage, builtin_clone_options);

	if (argc == 0)
		usage_msg_opt(_("You must specify a repository to clone."),
			builtin_clone_usage, builtin_clone_options);

	if (option_single_branch == -1)
		option_single_branch = option_depth ? 1 : 0;

	if (option_mirror)
		option_bare = 1;

	if (option_bare) {
		if (option_origin)
			die(_("--bare and --origin %s options are incompatible."),
			    option_origin);
		if (real_git_dir)
			die(_("--bare and --separate-git-dir are incompatible."));
		option_no_checkout = 1;
	}

	if (!option_origin)
		option_origin = "origin";

	repo_name = argv[0];

	path = get_repo_path(repo_name, &is_bundle);
	if (path)
		repo = xstrdup(absolute_path(repo_name));
	else if (!strchr(repo_name, ':'))
		die(_("repository '%s' does not exist"), repo_name);
	else
		repo = repo_name;

	/* no need to be strict, transport_set_option() will validate it again */
	if (option_depth && atoi(option_depth) < 1)
		die(_("depth %s is not a positive number"), option_depth);

	if (argc == 2)
		dir = xstrdup(argv[1]);
	else
		dir = guess_dir_name(repo_name, is_bundle, option_bare);
	strip_trailing_slashes(dir);

	dest_exists = !stat(dir, &buf);
	if (dest_exists && !is_empty_dir(dir))
		die(_("destination path '%s' already exists and is not "
			"an empty directory."), dir);

	strbuf_addf(&reflog_msg, "clone: from %s", repo);

	if (option_bare)
		work_tree = NULL;
	else {
		work_tree = getenv("GIT_WORK_TREE");
		if (work_tree && !stat(work_tree, &buf))
			die(_("working tree '%s' already exists."), work_tree);
	}

	if (option_bare || work_tree)
		git_dir = xstrdup(dir);
	else {
		work_tree = dir;
		git_dir = mkpathdup("%s/.git", dir);
	}

	if (!option_bare) {
		junk_work_tree = work_tree;
		if (safe_create_leading_directories_const(work_tree) < 0)
			die_errno(_("could not create leading directories of '%s'"),
				  work_tree);
		if (!dest_exists && mkdir(work_tree, 0777))
			die_errno(_("could not create work tree dir '%s'."),
				  work_tree);
		set_git_work_tree(work_tree);
	}
	junk_git_dir = git_dir;
	atexit(remove_junk);
	sigchain_push_common(remove_junk_on_signal);

	if (safe_create_leading_directories_const(git_dir) < 0)
		die(_("could not create leading directories of '%s'"), git_dir);

	set_git_dir_init(git_dir, real_git_dir, 0);
	if (real_git_dir) {
		git_dir = real_git_dir;
		junk_git_dir = real_git_dir;
	}

	if (0 <= option_verbosity) {
		if (option_bare)
			fprintf(stderr, _("Cloning into bare repository '%s'...\n"), dir);
		else
			fprintf(stderr, _("Cloning into '%s'...\n"), dir);
	}
	init_db(option_template, INIT_DB_QUIET);
	write_config(&option_config);

	git_config(git_default_config, NULL);

	if (option_bare) {
		if (option_mirror)
			src_ref_prefix = "refs/";
		strbuf_addstr(&branch_top, src_ref_prefix);

		git_config_set("core.bare", "true");
	} else {
		strbuf_addf(&branch_top, "refs/remotes/%s/", option_origin);
	}

	strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top.buf);
	strbuf_addf(&key, "remote.%s.url", option_origin);
	git_config_set(key.buf, repo);
	strbuf_reset(&key);

	if (option_reference.nr)
		setup_reference();
	else if (option_dissociate) {
		warning(_("--dissociate given, but there is no --reference"));
		option_dissociate = 0;
	}

	fetch_pattern = value.buf;
	refspec = parse_fetch_refspec(1, &fetch_pattern);

	strbuf_reset(&value);

	remote = remote_get(option_origin);
	transport = transport_get(remote, remote->url[0]);
	path = get_repo_path(remote->url[0], &is_bundle);
	is_local = option_local != 0 && path && !is_bundle;
	if (is_local) {
		if (option_depth)
			warning(_("--depth is ignored in local clones; use file:// instead."));
		if (!access(mkpath("%s/shallow", path), F_OK)) {
			if (option_local > 0)
				warning(_("source repository is shallow, ignoring --local"));
			is_local = 0;
		}
	}
	if (option_local > 0 && !is_local)
		warning(_("--local is ignored"));
	transport->cloning = 1;

	if (!transport->get_refs_list || (!is_local && !transport->fetch))
		die(_("Don't know how to clone %s"), transport->url);

	transport_set_option(transport, TRANS_OPT_KEEP, "yes");

	if (option_depth)
		transport_set_option(transport, TRANS_OPT_DEPTH,
				     option_depth);
	if (option_single_branch)
		transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");

	transport_set_verbosity(transport, option_verbosity, option_progress);

	if (option_upload_pack)
		transport_set_option(transport, TRANS_OPT_UPLOADPACK,
				     option_upload_pack);

	if (transport->smart_options && !option_depth)
		transport->smart_options->check_self_contained_and_connected = 1;

	refs = transport_get_remote_refs(transport);

	if (refs) {
		mapped_refs = wanted_peer_refs(refs, refspec);
		/*
		 * transport_get_remote_refs() may return refs with null sha-1
		 * in mapped_refs (see struct transport->get_refs_list
		 * comment). In that case we need fetch it early because
		 * remote_head code below relies on it.
		 *
		 * for normal clones, transport_get_remote_refs() should
		 * return reliable ref set, we can delay cloning until after
		 * remote HEAD check.
		 */
		for (ref = refs; ref; ref = ref->next)
			if (is_null_sha1(ref->old_sha1)) {
				complete_refs_before_fetch = 0;
				break;
			}

		if (!is_local && !complete_refs_before_fetch)
			transport_fetch_refs(transport, mapped_refs);

		remote_head = find_ref_by_name(refs, "HEAD");
		remote_head_points_at =
			guess_remote_head(remote_head, mapped_refs, 0);

		if (option_branch) {
			our_head_points_at =
				find_remote_branch(mapped_refs, option_branch);

			if (!our_head_points_at)
				die(_("Remote branch %s not found in upstream %s"),
				    option_branch, option_origin);
		}
		else
			our_head_points_at = remote_head_points_at;
	}
	else {
		if (option_branch)
			die(_("Remote branch %s not found in upstream %s"),
					option_branch, option_origin);

		warning(_("You appear to have cloned an empty repository."));
		mapped_refs = NULL;
		our_head_points_at = NULL;
		remote_head_points_at = NULL;
		remote_head = NULL;
		option_no_checkout = 1;
		if (!option_bare)
			install_branch_config(0, "master", option_origin,
					      "refs/heads/master");
	}

	write_refspec_config(src_ref_prefix, our_head_points_at,
			remote_head_points_at, &branch_top);

	if (is_local)
		clone_local(path, git_dir);
	else if (refs && complete_refs_before_fetch)
		transport_fetch_refs(transport, mapped_refs);

	update_remote_refs(refs, mapped_refs, remote_head_points_at,
			   branch_top.buf, reflog_msg.buf, transport, !is_local);

	update_head(our_head_points_at, remote_head, reflog_msg.buf);

	transport_unlock_pack(transport);
	transport_disconnect(transport);

	if (option_dissociate)
		dissociate_from_references();

	junk_mode = JUNK_LEAVE_REPO;
	err = checkout();

	strbuf_release(&reflog_msg);
	strbuf_release(&branch_top);
	strbuf_release(&key);
	strbuf_release(&value);
	junk_mode = JUNK_LEAVE_ALL;

	free(refspec);
	return err;
}
Exemplo n.º 6
0
int cmd_clone(int argc, const char **argv, const char *prefix)
{
	int is_bundle = 0;
	struct stat buf;
	const char *repo_name, *repo, *work_tree, *git_dir;
	char *path, *dir;
	int dest_exists;
	const struct ref *refs, *remote_head;
	const struct ref *remote_head_points_at;
	const struct ref *our_head_points_at;
	struct ref *mapped_refs;
	struct strbuf key = STRBUF_INIT, value = STRBUF_INIT;
	struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
	struct transport *transport = NULL;
	char *src_ref_prefix = "refs/heads/";
	int err = 0;

	struct refspec *refspec;
	const char *fetch_pattern;

	junk_pid = getpid();

	argc = parse_options(argc, argv, prefix, builtin_clone_options,
			     builtin_clone_usage, 0);

	if (argc > 2)
		usage_msg_opt("Too many arguments.",
			builtin_clone_usage, builtin_clone_options);

	if (argc == 0)
		usage_msg_opt("You must specify a repository to clone.",
			builtin_clone_usage, builtin_clone_options);

	if (option_mirror)
		option_bare = 1;

	if (option_bare) {
		if (option_origin)
			die("--bare and --origin %s options are incompatible.",
			    option_origin);
		option_no_checkout = 1;
	}

	if (!option_origin)
		option_origin = "origin";

	repo_name = argv[0];

	path = get_repo_path(repo_name, &is_bundle);
	if (path)
		repo = xstrdup(make_nonrelative_path(repo_name));
	else if (!strchr(repo_name, ':'))
		repo = xstrdup(make_absolute_path(repo_name));
	else
		repo = repo_name;

	if (argc == 2)
		dir = xstrdup(argv[1]);
	else
		dir = guess_dir_name(repo_name, is_bundle, option_bare);
	strip_trailing_slashes(dir);

	dest_exists = !stat(dir, &buf);
	if (dest_exists && !is_empty_dir(dir))
		die("destination path '%s' already exists and is not "
			"an empty directory.", dir);

	strbuf_addf(&reflog_msg, "clone: from %s", repo);

	if (option_bare)
		work_tree = NULL;
	else {
		work_tree = getenv("GIT_WORK_TREE");
		if (work_tree && !stat(work_tree, &buf))
			die("working tree '%s' already exists.", work_tree);
	}

	if (option_bare || work_tree)
		git_dir = xstrdup(dir);
	else {
		work_tree = dir;
		git_dir = xstrdup(mkpath("%s/.git", dir));
	}

	if (!option_bare) {
		junk_work_tree = work_tree;
		if (safe_create_leading_directories_const(work_tree) < 0)
			die_errno("could not create leading directories of '%s'",
				  work_tree);
		if (!dest_exists && mkdir(work_tree, 0755))
			die_errno("could not create work tree dir '%s'.",
				  work_tree);
		set_git_work_tree(work_tree);
	}
	junk_git_dir = git_dir;
	atexit(remove_junk);
	sigchain_push_common(remove_junk_on_signal);

	setenv(CONFIG_ENVIRONMENT, mkpath("%s/config", git_dir), 1);

	if (safe_create_leading_directories_const(git_dir) < 0)
		die("could not create leading directories of '%s'", git_dir);
	set_git_dir(make_absolute_path(git_dir));

	init_db(option_template, option_quiet ? INIT_DB_QUIET : 0);

	/*
	 * At this point, the config exists, so we do not need the
	 * environment variable.  We actually need to unset it, too, to
	 * re-enable parsing of the global configs.
	 */
	unsetenv(CONFIG_ENVIRONMENT);

	if (option_reference)
		setup_reference(git_dir);

	git_config(git_default_config, NULL);

	if (option_bare) {
		if (option_mirror)
			src_ref_prefix = "refs/";
		strbuf_addstr(&branch_top, src_ref_prefix);

		git_config_set("core.bare", "true");
	} else {
		strbuf_addf(&branch_top, "refs/remotes/%s/", option_origin);
	}

	strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top.buf);

	if (option_mirror || !option_bare) {
		/* Configure the remote */
		strbuf_addf(&key, "remote.%s.fetch", option_origin);
		git_config_set_multivar(key.buf, value.buf, "^$", 0);
		strbuf_reset(&key);

		if (option_mirror) {
			strbuf_addf(&key, "remote.%s.mirror", option_origin);
			git_config_set(key.buf, "true");
			strbuf_reset(&key);
		}

		strbuf_addf(&key, "remote.%s.url", option_origin);
		git_config_set(key.buf, repo);
		strbuf_reset(&key);
	}

	fetch_pattern = value.buf;
	refspec = parse_fetch_refspec(1, &fetch_pattern);

	strbuf_reset(&value);

	if (path && !is_bundle) {
		refs = clone_local(path, git_dir);
		mapped_refs = wanted_peer_refs(refs, refspec);
	} else {
		struct remote *remote = remote_get(argv[0]);
		transport = transport_get(remote, remote->url[0]);

		if (!transport->get_refs_list || !transport->fetch)
			die("Don't know how to clone %s", transport->url);

		transport_set_option(transport, TRANS_OPT_KEEP, "yes");

		if (option_depth)
			transport_set_option(transport, TRANS_OPT_DEPTH,
					     option_depth);

		if (option_quiet)
			transport->verbose = -1;
		else if (option_verbose)
			transport->verbose = 1;

		if (option_progress)
			transport->progress = 1;

		if (option_upload_pack)
			transport_set_option(transport, TRANS_OPT_UPLOADPACK,
					     option_upload_pack);

		refs = transport_get_remote_refs(transport);
		if (refs) {
			mapped_refs = wanted_peer_refs(refs, refspec);
			transport_fetch_refs(transport, mapped_refs);
		}
	}

	if (refs) {
		clear_extra_refs();

		write_remote_refs(mapped_refs);

		remote_head = find_ref_by_name(refs, "HEAD");
		remote_head_points_at =
			guess_remote_head(remote_head, mapped_refs, 0);

		if (option_branch) {
			struct strbuf head = STRBUF_INIT;
			strbuf_addstr(&head, src_ref_prefix);
			strbuf_addstr(&head, option_branch);
			our_head_points_at =
				find_ref_by_name(mapped_refs, head.buf);
			strbuf_release(&head);

			if (!our_head_points_at) {
				warning("Remote branch %s not found in "
					"upstream %s, using HEAD instead",
					option_branch, option_origin);
				our_head_points_at = remote_head_points_at;
			}
		}
		else
			our_head_points_at = remote_head_points_at;
	}
	else {
		warning("You appear to have cloned an empty repository.");
		our_head_points_at = NULL;
		remote_head_points_at = NULL;
		remote_head = NULL;
		option_no_checkout = 1;
		if (!option_bare)
			install_branch_config(0, "master", option_origin,
					      "refs/heads/master");
	}

	if (remote_head_points_at && !option_bare) {
		struct strbuf head_ref = STRBUF_INIT;
		strbuf_addstr(&head_ref, branch_top.buf);
		strbuf_addstr(&head_ref, "HEAD");
		create_symref(head_ref.buf,
			      remote_head_points_at->peer_ref->name,
			      reflog_msg.buf);
	}

	if (our_head_points_at) {
		/* Local default branch link */
		create_symref("HEAD", our_head_points_at->name, NULL);
		if (!option_bare) {
			const char *head = skip_prefix(our_head_points_at->name,
						       "refs/heads/");
			update_ref(reflog_msg.buf, "HEAD",
				   our_head_points_at->old_sha1,
				   NULL, 0, DIE_ON_ERR);
			install_branch_config(0, head, option_origin,
					      our_head_points_at->name);
		}
	} else if (remote_head) {
		/* Source had detached HEAD pointing somewhere. */
		if (!option_bare) {
			update_ref(reflog_msg.buf, "HEAD",
				   remote_head->old_sha1,
				   NULL, REF_NODEREF, DIE_ON_ERR);
			our_head_points_at = remote_head;
		}
	} else {
		/* Nothing to checkout out */
		if (!option_no_checkout)
			warning("remote HEAD refers to nonexistent ref, "
				"unable to checkout.\n");
		option_no_checkout = 1;
	}

	if (transport) {
		transport_unlock_pack(transport);
		transport_disconnect(transport);
	}

	if (!option_no_checkout) {
		struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
		struct unpack_trees_options opts;
		struct tree *tree;
		struct tree_desc t;
		int fd;

		/* We need to be in the new work tree for the checkout */
		setup_work_tree();

		fd = hold_locked_index(lock_file, 1);

		memset(&opts, 0, sizeof opts);
		opts.update = 1;
		opts.merge = 1;
		opts.fn = oneway_merge;
		opts.verbose_update = !option_quiet;
		opts.src_index = &the_index;
		opts.dst_index = &the_index;

		tree = parse_tree_indirect(our_head_points_at->old_sha1);
		parse_tree(tree);
		init_tree_desc(&t, tree->buffer, tree->size);
		unpack_trees(1, &t, &opts);

		if (write_cache(fd, active_cache, active_nr) ||
		    commit_locked_index(lock_file))
			die("unable to write new index file");

		err |= run_hook(NULL, "post-checkout", sha1_to_hex(null_sha1),
				sha1_to_hex(our_head_points_at->old_sha1), "1",
				NULL);

		if (!err && option_recursive)
			err = run_command_v_opt(argv_submodule, RUN_GIT_CMD);
	}

	strbuf_release(&reflog_msg);
	strbuf_release(&branch_top);
	strbuf_release(&key);
	strbuf_release(&value);
	junk_pid = 0;
	return err;
}
Exemplo n.º 7
0
int cmd_fetch(int argc, const char **argv, const char *prefix)
{
	struct remote *remote;
	int i;
	static const char **refs = NULL;
	int ref_nr = 0;
	int exit_code;

	/* Record the command line for the reflog */
	strbuf_addstr(&default_rla, "fetch");
	for (i = 1; i < argc; i++)
		strbuf_addf(&default_rla, " %s", argv[i]);

	argc = parse_options(argc, argv, prefix,
			     builtin_fetch_options, builtin_fetch_usage, 0);

	if (argc == 0)
		remote = remote_get(NULL);
	else
		remote = remote_get(argv[0]);

	if (!remote)
		die("Where do you want to fetch from today?");

	transport = transport_get(remote, remote->url[0]);
	if (verbosity >= 2)
		transport->verbose = 1;
	if (verbosity < 0)
		transport->verbose = -1;
	if (upload_pack)
		set_option(TRANS_OPT_UPLOADPACK, upload_pack);
	if (keep)
		set_option(TRANS_OPT_KEEP, "yes");
	if (depth)
		set_option(TRANS_OPT_DEPTH, depth);

	if (argc > 1) {
		int j = 0;
		refs = xcalloc(argc + 1, sizeof(const char *));
		for (i = 1; i < argc; i++) {
			if (!strcmp(argv[i], "tag")) {
				char *ref;
				i++;
				if (i >= argc)
					die("You need to specify a tag name.");
				ref = xmalloc(strlen(argv[i]) * 2 + 22);
				strcpy(ref, "refs/tags/");
				strcat(ref, argv[i]);
				strcat(ref, ":refs/tags/");
				strcat(ref, argv[i]);
				refs[j++] = ref;
			} else
				refs[j++] = argv[i];
		}
		refs[j] = NULL;
		ref_nr = j;
	}

	sigchain_push_common(unlock_pack_on_signal);
	atexit(unlock_pack);
	exit_code = do_fetch(transport,
			parse_fetch_refspec(ref_nr, refs), ref_nr);
	transport_disconnect(transport);
	transport = NULL;
	return exit_code;
}
Exemplo n.º 8
0
static struct child_process *get_helper(struct transport *transport)
{
	struct helper_data *data = transport->data;
	struct strbuf buf = STRBUF_INIT;
	struct child_process *helper;
	const char **refspecs = NULL;
	int refspec_nr = 0;
	int refspec_alloc = 0;
	int duped;
	int code;

	if (data->helper)
		return data->helper;

	helper = xcalloc(1, sizeof(*helper));
	helper->in = -1;
	helper->out = -1;
	helper->err = 0;
	helper->argv = xcalloc(4, sizeof(*helper->argv));
	strbuf_addf(&buf, "git-remote-%s", data->name);
	helper->argv[0] = strbuf_detach(&buf, NULL);
	helper->argv[1] = transport->remote->name;
	helper->argv[2] = remove_ext_force(transport->url);
	helper->git_cmd = 0;
	helper->silent_exec_failure = 1;
	code = start_command(helper);
	if (code < 0 && errno == ENOENT)
		die("Unable to find remote helper for '%s'", data->name);
	else if (code != 0)
		exit(code);

	data->helper = helper;
	data->no_disconnect_req = 0;

	/*
	 * Open the output as FILE* so strbuf_getline() can be used.
	 * Do this with duped fd because fclose() will close the fd,
	 * and stuff like taking over will require the fd to remain.
	 */
	duped = dup(helper->out);
	if (duped < 0)
		die_errno("Can't dup helper output fd");
	data->out = xfdopen(duped, "r");

	write_constant(helper->in, "capabilities\n");

	while (1) {
		const char *capname;
		int mandatory = 0;
		recvline(data, &buf);

		if (!*buf.buf)
			break;

		if (*buf.buf == '*') {
			capname = buf.buf + 1;
			mandatory = 1;
		} else
			capname = buf.buf;

		if (debug)
			fprintf(stderr, "Debug: Got cap %s\n", capname);
		if (!strcmp(capname, "fetch"))
			data->fetch = 1;
		else if (!strcmp(capname, "option"))
			data->option = 1;
		else if (!strcmp(capname, "push"))
			data->push = 1;
		else if (!strcmp(capname, "import"))
			data->import = 1;
		else if (!data->refspecs && !prefixcmp(capname, "refspec ")) {
			ALLOC_GROW(refspecs,
				   refspec_nr + 1,
				   refspec_alloc);
			refspecs[refspec_nr++] = strdup(buf.buf + strlen("refspec "));
		} else if (!strcmp(capname, "connect")) {
			data->connect = 1;
		} else if (mandatory) {
			die("Unknown mandatory capability %s. This remote "
			    "helper probably needs newer version of Git.\n",
			    capname);
		}
	}
	if (refspecs) {
		int i;
		data->refspec_nr = refspec_nr;
		data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
		for (i = 0; i < refspec_nr; i++) {
			free((char *)refspecs[i]);
		}
		free(refspecs);
	}
	strbuf_release(&buf);
	if (debug)
		fprintf(stderr, "Debug: Capabilities complete.\n");
	return data->helper;
}