1 files changed, 360 insertions, 170 deletions

diff --git a/builtin/clone.c b/builtin/clone.c
index 49c838fd3f..bbd5c96237 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -37,20 +37,31 @@ static const char * const builtin_clone_usage[] = {
 	NULL
 };
 
-static int option_no_checkout, option_bare, option_mirror;
+static int option_no_checkout, option_bare, option_mirror, option_single_branch = -1;
 static int option_local, option_no_hardlinks, option_shared, option_recursive;
-static char *option_template, *option_reference, *option_depth;
+static char *option_template, *option_depth;
 static char *option_origin = NULL;
 static char *option_branch = NULL;
 static const char *real_git_dir;
 static char *option_upload_pack = "git-upload-pack";
 static int option_verbosity;
-static int option_progress;
+static int option_progress = -1;
+static struct string_list option_config;
+static struct string_list option_reference;
+
+static int opt_parse_reference(const struct option *opt, const char *arg, int unset)
+{
+	struct string_list *option_reference = opt->value;
+	if (!arg)
+		return -1;
+	string_list_append(option_reference, arg);
+	return 0;
+}
 
 static struct option builtin_clone_options[] = {
 	OPT__VERBOSITY(&option_verbosity),
-	OPT_BOOLEAN(0, "progress", &option_progress,
-			"force progress reporting"),
+	OPT_BOOL(0, "progress", &option_progress,
+		 "force progress reporting"),
 	OPT_BOOLEAN('n', "no-checkout", &option_no_checkout,
 		    "don't create a checkout"),
 	OPT_BOOLEAN(0, "bare", &option_bare, "create a bare repository"),
@@ -71,19 +82,22 @@ static struct option builtin_clone_options[] = {
 		    "initialize submodules in the clone"),
 	OPT_STRING(0, "template", &option_template, "template-directory",
 		   "directory from which templates will be used"),
-	OPT_STRING(0, "reference", &option_reference, "repo",
-		   "reference repository"),
-	OPT_STRING('o', "origin", &option_origin, "branch",
-		   "use <branch> instead of 'origin' to track upstream"),
+	OPT_CALLBACK(0 , "reference", &option_reference, "repo",
+		     "reference repository", &opt_parse_reference),
+	OPT_STRING('o', "origin", &option_origin, "name",
+		   "use <name> instead of 'origin' to track upstream"),
 	OPT_STRING('b', "branch", &option_branch, "branch",
 		   "checkout <branch> instead of the remote's HEAD"),
 	OPT_STRING('u', "upload-pack", &option_upload_pack, "path",
 		   "path to git-upload-pack on the remote"),
 	OPT_STRING(0, "depth", &option_depth, "depth",
 		    "create a shallow clone of that depth"),
-	OPT_STRING('L', "separate-git-dir", &real_git_dir, "gitdir",
+	OPT_BOOL(0, "single-branch", &option_single_branch,
+		    "clone only one branch, HEAD or --branch"),
+	OPT_STRING(0, "separate-git-dir", &real_git_dir, "gitdir",
 		   "separate git dir from working tree"),
-
+	OPT_STRING_LIST('c', "config", &option_config, "key=value",
+			"set config inside the new repository"),
 	OPT_END()
 };
 
@@ -93,7 +107,7 @@ static const char *argv_submodule[] = {
 
 static char *get_repo_path(const char *repo, int *is_bundle)
 {
-	static char *suffix[] = { "/.git", ".git", "" };
+	static char *suffix[] = { "/.git", "", ".git/.git", ".git" };
 	static char *bundle_suffix[] = { ".bundle", "" };
 	struct stat st;
 	int i;
@@ -101,9 +115,26 @@ static char *get_repo_path(const char *repo, int *is_bundle)
 	for (i = 0; i < ARRAY_SIZE(suffix); i++) {
 		const char *path;
 		path = mkpath("%s%s", repo, suffix[i]);
-		if (is_directory(path)) {
+		if (stat(path, &st))
+			continue;
+		if (S_ISDIR(st.st_mode) && is_git_directory(path)) {
 			*is_bundle = 0;
 			return xstrdup(absolute_path(path));
+		} else if (S_ISREG(st.st_mode) && st.st_size > 8) {
+			/* Is it a "gitfile"? */
+			char signature[8];
+			int len, fd = open(path, O_RDONLY);
+			if (fd < 0)
+				continue;
+			len = read_in_full(fd, signature, 8);
+			close(fd);
+			if (len != 8 || strncmp(signature, "gitdir: ", 8))
+				continue;
+			path = read_gitfile(path);
+			if (path) {
+				*is_bundle = 0;
+				return xstrdup(absolute_path(path));
+			}
 		}
 	}
 
@@ -197,39 +228,69 @@ static void strip_trailing_slashes(char *dir)
 	*end = '\0';
 }
 
-static void setup_reference(const char *repo)
+static int add_one_reference(struct string_list_item *item, void *cb_data)
 {
-	const char *ref_git;
-	char *ref_git_copy;
-
-	struct remote *remote;
-	struct transport *transport;
-	const struct ref *extra;
-
-	ref_git = real_path(option_reference);
-
-	if (is_directory(mkpath("%s/.git/objects", ref_git)))
-		ref_git = mkpath("%s/.git", ref_git);
-	else if (!is_directory(mkpath("%s/objects", ref_git)))
+	char *ref_git;
+	struct strbuf alternate = STRBUF_INIT;
+
+	/* Beware: real_path() and mkpath() return static buffer */
+	ref_git = xstrdup(real_path(item->string));
+	if (is_directory(mkpath("%s/.git/objects", ref_git))) {
+		char *ref_git_git = xstrdup(mkpath("%s/.git", ref_git));
+		free(ref_git);
+		ref_git = ref_git_git;
+	} else if (!is_directory(mkpath("%s/objects", ref_git)))
 		die(_("reference repository '%s' is not a local directory."),
-		    option_reference);
+		    item->string);
 
-	ref_git_copy = xstrdup(ref_git);
-
-	add_to_alternates_file(ref_git_copy);
+	strbuf_addf(&alternate, "%s/objects", ref_git);
+	add_to_alternates_file(alternate.buf);
+	strbuf_release(&alternate);
+	free(ref_git);
+	return 0;
+}
 
-	remote = remote_get(ref_git_copy);
-	transport = transport_get(remote, ref_git_copy);
-	for (extra = transport_get_remote_refs(transport); extra;
-	     extra = extra->next)
-		add_extra_ref(extra->name, extra->old_sha1, 0);
+static void setup_reference(void)
+{
+	for_each_string_list(&option_reference, add_one_reference, NULL);
+}
 
-	transport_disconnect(transport);
+static void copy_alternates(struct strbuf *src, struct strbuf *dst,
+			    const char *src_repo)
+{
+	/*
+	 * Read from the source objects/info/alternates file
+	 * and copy the entries to corresponding file in the
+	 * destination repository with add_to_alternates_file().
+	 * Both src and dst have "$path/objects/info/alternates".
+	 *
+	 * Instead of copying bit-for-bit from the original,
+	 * we need to append to existing one so that the already
+	 * created entry via "clone -s" is not lost, and also
+	 * to turn entries with paths relative to the original
+	 * absolute, so that they can be used in the new repository.
+	 */
+	FILE *in = fopen(src->buf, "r");
+	struct strbuf line = STRBUF_INIT;
 
-	free(ref_git_copy);
+	while (strbuf_getline(&line, in, '\n') != EOF) {
+		char *abs_path, abs_buf[PATH_MAX];
+		if (!line.len || line.buf[0] == '#')
+			continue;
+		if (is_absolute_path(line.buf)) {
+			add_to_alternates_file(line.buf);
+			continue;
+		}
+		abs_path = mkpath("%s/objects/%s", src_repo, line.buf);
+		normalize_path_copy(abs_buf, abs_path);
+		add_to_alternates_file(abs_buf);
+	}
+	strbuf_release(&line);
+	fclose(in);
 }
 
-static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest)
+static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
+				   const char *src_repo, int src_baselen)
 {
 	struct dirent *de;
 	struct stat buf;
@@ -265,7 +326,14 @@ static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest)
 		}
 		if (S_ISDIR(buf.st_mode)) {
 			if (de->d_name[0] != '.')
-				copy_or_link_directory(src, dest);
+				copy_or_link_directory(src, dest,
+						       src_repo, src_baselen);
+			continue;
+		}
+
+		/* Files that cannot be copied bit-for-bit... */
+		if (!strcmp(src->buf + src_baselen, "/info/alternates")) {
+			copy_alternates(src, dest, src_repo);
 			continue;
 		}
 
@@ -284,32 +352,25 @@ static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest)
 	closedir(dir);
 }
 
-static const struct ref *clone_local(const char *src_repo,
-				     const char *dest_repo)
+static void clone_local(const char *src_repo, const char *dest_repo)
 {
-	const struct ref *ret;
-	struct strbuf src = STRBUF_INIT;
-	struct strbuf dest = STRBUF_INIT;
-	struct remote *remote;
-	struct transport *transport;
-
-	if (option_shared)
-		add_to_alternates_file(src_repo);
-	else {
+	if (option_shared) {
+		struct strbuf alt = STRBUF_INIT;
+		strbuf_addf(&alt, "%s/objects", src_repo);
+		add_to_alternates_file(alt.buf);
+		strbuf_release(&alt);
+	} else {
+		struct strbuf src = STRBUF_INIT;
+		struct strbuf dest = STRBUF_INIT;
 		strbuf_addf(&src, "%s/objects", src_repo);
 		strbuf_addf(&dest, "%s/objects", dest_repo);
-		copy_or_link_directory(&src, &dest);
+		copy_or_link_directory(&src, &dest, src_repo, src.len);
 		strbuf_release(&src);
 		strbuf_release(&dest);
 	}
 
-	remote = remote_get(src_repo);
-	transport = transport_get(remote, src_repo);
-	ret = transport_get_remote_refs(transport);
-	transport_disconnect(transport);
 	if (0 <= option_verbosity)
 		printf(_("done.\n"));
-	return ret;
 }
 
 static const char *junk_work_tree;
@@ -340,14 +401,54 @@ static void remove_junk_on_signal(int signo)
 	raise(signo);
 }
 
+static struct ref *find_remote_branch(const struct ref *refs, const char *branch)
+{
+	struct ref *ref;
+	struct strbuf head = STRBUF_INIT;
+	strbuf_addstr(&head, "refs/heads/");
+	strbuf_addstr(&head, branch);
+	ref = find_ref_by_name(refs, head.buf);
+	strbuf_release(&head);
+
+	if (ref)
+		return ref;
+
+	strbuf_addstr(&head, "refs/tags/");
+	strbuf_addstr(&head, branch);
+	ref = find_ref_by_name(refs, head.buf);
+	strbuf_release(&head);
+
+	return ref;
+}
+
 static struct ref *wanted_peer_refs(const struct ref *refs,
 		struct refspec *refspec)
 {
-	struct ref *local_refs = NULL;
-	struct ref **tail = &local_refs;
+	struct ref *head = copy_ref(find_ref_by_name(refs, "HEAD"));
+	struct ref *local_refs = head;
+	struct ref **tail = head ? &head->next : &local_refs;
+
+	if (option_single_branch) {
+		struct ref *remote_head = NULL;
+
+		if (!option_branch)
+			remote_head = guess_remote_head(head, refs, 0);
+		else
+			remote_head = find_remote_branch(refs, option_branch);
+
+		if (!remote_head && option_branch)
+			warning(_("Could not find remote branch %s to clone."),
+				option_branch);
+		else {
+			get_fetch_map(remote_head, refspec, &tail, 0);
+
+			/* if --branch=tag, pull the requested tag explicitly */
+			get_fetch_map(remote_head, tag_refspec, &tail, 0);
+		}
+	} else
+		get_fetch_map(refs, refspec, &tail, 0);
 
-	get_fetch_map(refs, refspec, &tail, 0);
-	if (!option_mirror)
+	if (!option_mirror && !option_single_branch)
 		get_fetch_map(refs, tag_refspec, &tail, 0);
 
 	return local_refs;
@@ -357,11 +458,153 @@ static void write_remote_refs(const struct ref *local_refs)
 {
 	const struct ref *r;
 
-	for (r = local_refs; r; r = r->next)
-		add_extra_ref(r->peer_ref->name, r->old_sha1, 0);
+	for (r = local_refs; r; r = r->next) {
+		if (!r->peer_ref)
+			continue;
+		add_packed_ref(r->peer_ref->name, r->old_sha1);
+	}
 
 	pack_refs(PACK_REFS_ALL);
-	clear_extra_refs();
+}
+
+static void write_followtags(const struct ref *refs, const char *msg)
+{
+	const struct ref *ref;
+	for (ref = refs; ref; ref = ref->next) {
+		if (prefixcmp(ref->name, "refs/tags/"))
+			continue;
+		if (!suffixcmp(ref->name, "^{}"))
+			continue;
+		if (!has_sha1_file(ref->old_sha1))
+			continue;
+		update_ref(msg, ref->name, ref->old_sha1,
+			   NULL, 0, DIE_ON_ERR);
+	}
+}
+
+static void update_remote_refs(const struct ref *refs,
+			       const struct ref *mapped_refs,
+			       const struct ref *remote_head_points_at,
+			       const char *branch_top,
+			       const char *msg)
+{
+	if (refs) {
+		write_remote_refs(mapped_refs);
+		if (option_single_branch)
+			write_followtags(refs, msg);
+	}
+
+	if (remote_head_points_at && !option_bare) {
+		struct strbuf head_ref = STRBUF_INIT;
+		strbuf_addstr(&head_ref, branch_top);
+		strbuf_addstr(&head_ref, "HEAD");
+		create_symref(head_ref.buf,
+			      remote_head_points_at->peer_ref->name,
+			      msg);
+	}
+}
+
+static void update_head(const struct ref *our, const struct ref *remote,
+			const char *msg)
+{
+	if (our && !prefixcmp(our->name, "refs/heads/")) {
+		/* Local default branch link */
+		create_symref("HEAD", our->name, NULL);
+		if (!option_bare) {
+			const char *head = skip_prefix(our->name, "refs/heads/");
+			update_ref(msg, "HEAD", our->old_sha1, NULL, 0, DIE_ON_ERR);
+			install_branch_config(0, head, option_origin, our->name);
+		}
+	} else if (our) {
+		struct commit *c = lookup_commit_reference(our->old_sha1);
+		/* --branch specifies a non-branch (i.e. tags), detach HEAD */
+		update_ref(msg, "HEAD", c->object.sha1,
+			   NULL, REF_NODEREF, DIE_ON_ERR);
+	} else if (remote) {
+		/*
+		 * We know remote HEAD points to a non-branch, or
+		 * HEAD points to a branch but we don't know which one.
+		 * Detach HEAD in all these cases.
+		 */
+		update_ref(msg, "HEAD", remote->old_sha1,
+			   NULL, REF_NODEREF, DIE_ON_ERR);
+	}
+}
+
+static int checkout(void)
+{
+	unsigned char sha1[20];
+	char *head;
+	struct lock_file *lock_file;
+	struct unpack_trees_options opts;
+	struct tree *tree;
+	struct tree_desc t;
+	int err = 0, fd;
+
+	if (option_no_checkout)
+		return 0;
+
+	head = resolve_refdup("HEAD", sha1, 1, NULL);
+	if (!head) {
+		warning(_("remote HEAD refers to nonexistent ref, "
+			  "unable to checkout.\n"));
+		return 0;
+	}
+	if (!strcmp(head, "HEAD")) {
+		if (advice_detached_head)
+			detach_advice(sha1_to_hex(sha1));
+	} else {
+		if (prefixcmp(head, "refs/heads/"))
+			die(_("HEAD not found below refs/heads!"));
+	}
+	free(head);
+
+	/* We need to be in the new work tree for the checkout */
+	setup_work_tree();
+
+	lock_file = xcalloc(1, sizeof(struct lock_file));
+	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_verbosity > 0);
+	opts.src_index = &the_index;
+	opts.dst_index = &the_index;
+
+	tree = parse_tree_indirect(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(sha1), "1", NULL);
+
+	if (!err && option_recursive)
+		err = run_command_v_opt(argv_submodule, RUN_GIT_CMD);
+
+	return err;
+}
+
+static int write_one_config(const char *key, const char *value, void *data)
+{
+	return git_config_set_multivar(key, value ? value : "true", "^$", 0);
+}
+
+static void write_config(struct string_list *config)
+{
+	int i;
+
+	for (i = 0; i < config->nr; i++) {
+		if (git_config_parse_parameter(config->items[i].string,
+					       write_one_config, NULL) < 0)
+			die("unable to write parameters to config file");
+	}
 }
 
 int cmd_clone(int argc, const char **argv, const char *prefix)
@@ -375,11 +618,13 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	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;
-	char *src_ref_prefix = "refs/heads/";
-	int err = 0;
+	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;
@@ -398,6 +643,9 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		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;
 
@@ -477,11 +725,12 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 
 	if (0 <= option_verbosity) {
 		if (option_bare)
-			printf(_("Cloning into bare repository %s...\n"), dir);
+			printf(_("Cloning into bare repository '%s'...\n"), dir);
 		else
-			printf(_("Cloning into %s...\n"), dir);
+			printf(_("Cloning into '%s'...\n"), dir);
 	}
 	init_db(option_template, INIT_DB_QUIET);
+	write_config(&option_config);
 
 	/*
 	 * At this point, the config exists, so we do not need the
@@ -521,21 +770,18 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	git_config_set(key.buf, repo);
 	strbuf_reset(&key);
 
-	if (option_reference)
-		setup_reference(git_dir);
+	if (option_reference.nr)
+		setup_reference();
 
 	fetch_pattern = value.buf;
 	refspec = parse_fetch_refspec(1, &fetch_pattern);
 
 	strbuf_reset(&value);
 
-	if (is_local) {
-		refs = clone_local(path, git_dir);
-		mapped_refs = wanted_peer_refs(refs, refspec);
-	} else {
-		struct remote *remote = remote_get(option_origin);
-		transport = transport_get(remote, remote->url[0]);
+	remote = remote_get(option_origin);
+	transport = transport_get(remote, remote->url[0]);
 
+	if (!is_local) {
 		if (!transport->get_refs_list || !transport->fetch)
 			die(_("Don't know how to clone %s"), transport->url);
 
@@ -544,49 +790,57 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		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);
-
-		refs = transport_get_remote_refs(transport);
-		if (refs) {
-			mapped_refs = wanted_peer_refs(refs, refspec);
-			transport_fetch_refs(transport, mapped_refs);
-		}
 	}
 
+	refs = transport_get_remote_refs(transport);
+
 	if (refs) {
-		clear_extra_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;
+			}
 
-		write_remote_refs(mapped_refs);
+		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) {
-			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;
-			}
+				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 {
 		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;
@@ -596,84 +850,20 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 					      "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 (is_local)
+		clone_local(path, git_dir);
+	else if (refs && complete_refs_before_fetch)
+		transport_fetch_refs(transport, mapped_refs);
 
-	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;
-	}
+	update_remote_refs(refs, mapped_refs, remote_head_points_at,
+			   branch_top.buf, reflog_msg.buf);
 
-	if (transport) {
-		transport_unlock_pack(transport);
-		transport_disconnect(transport);
-	}
+	update_head(our_head_points_at, remote_head, reflog_msg.buf);
 
-	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_verbosity > 0);
-		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);
-	}
+	transport_unlock_pack(transport);
+	transport_disconnect(transport);
+
+	err = checkout();
 
 	strbuf_release(&reflog_msg);
 	strbuf_release(&branch_top);