patchclone: allow detached checkout when --branch takes a tag

diff --git a/builtin/clone.c b/builtin/clone.c
index 8f29912..97af4bd 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -23,6 +23,7 @@
 #include "branch.h"
 #include "remote.h"
 #include "run-command.h"
+#include "tag.h"
 
 /*
  * Overall FIXMEs:
@@ -721,6 +722,14 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 			strbuf_release(&head);
 
 			if (!our_head_points_at) {
+				strbuf_addstr(&head, "refs/tags/");
+				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);
@@ -750,7 +759,16 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 			      reflog_msg.buf);
 	}
 
-	if (our_head_points_at) {
+	if (our_head_points_at &&
+	    !prefixcmp(our_head_points_at->name, "refs/tags/")) {
+		const struct ref *ref = our_head_points_at;
+		struct object *o;
+
+		/* Detached HEAD */
+		o = deref_tag(parse_object(ref->old_sha1), NULL, 0);
+		update_ref(reflog_msg.buf, "HEAD", o->sha1, NULL,
+			   REF_NODEREF, DIE_ON_ERR);
+	} else if (our_head_points_at) {
 		/* Local default branch link */
 		create_symref("HEAD", our_head_points_at->name, NULL);
 		if (!option_bare) {

diff --git a/t/t5601-clone.sh b/t/t5601-clone.sh
index 87ee016..49821eb 100755
--- a/t/t5601-clone.sh
+++ b/t/t5601-clone.sh
@@ -9,9 +9,9 @@ test_expect_success setup '
 	rm -fr .git &&
 	test_create_repo src &&
 	(
-		cd src
-		>file
-		git add file
+		cd src &&
+		>file &&
+		git add file &&
 		git commit -m initial
 	)
 

builtin/clone.c, t/t5601-clone.sh

diff --git a/builtin/clone.c b/builtin/clone.c
index 86db954..8dde1ea 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -720,12 +720,9 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		}
 	} 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;
-		}
+		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)
diff --git a/t/t5601-clone.sh b/t/t5601-clone.sh
index 49821eb..e0b8db6 100755
--- a/t/t5601-clone.sh
+++ b/t/t5601-clone.sh
@@ -12,7 +12,10 @@ test_expect_success setup '
 		cd src &&
 		>file &&
 		git add file &&
-		git commit -m initial
+		git commit -m initial &&
+		echo 1 >file &&
+		git add file &&
+		git commit -m updated
 	)
 
 '
@@ -88,6 +91,26 @@ test_expect_success 'clone --mirror' '
 
 '
 
+test_expect_success 'clone --mirror with detached HEAD' '
+
+	( cd src && git checkout HEAD^ && git rev-parse HEAD >../expected ) &&
+	git clone --mirror src mirror.detached &&
+	( cd src && git checkout - ) &&
+	GIT_DIR=mirror.detached git rev-parse HEAD >actual &&
+	test_cmp expected actual
+
+'
+
+test_expect_success 'clone --bare with detached HEAD' '
+
+	( cd src && git checkout HEAD^ && git rev-parse HEAD >../expected ) &&
+	git clone --bare src bare.detached &&
+	( cd src && git checkout - ) &&
+	GIT_DIR=bare.detached git rev-parse HEAD >actual &&
+	test_cmp expected actual
+
+'
+
 test_expect_success 'clone --bare names the local repository <name>.git' '
 
 	git clone --bare src &&

diff --git a/builtin/clone.c b/builtin/clone.c
index 8dde1ea..100056d 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -448,6 +448,63 @@ static void write_remote_refs(const struct ref *local_refs)
 	clear_extra_refs();
 }
 
+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 (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);
@@ -722,13 +779,6 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		/* Source had detached HEAD pointing somewhere. */
 		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) {
@@ -736,42 +786,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		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_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);
-	}
+	err = checkout();
 
 	strbuf_release(&reflog_msg);
 	strbuf_release(&branch_top);

diff --git a/builtin/clone.c b/builtin/clone.c
index 100056d..914fd6b 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -727,7 +727,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 
 		if (option_branch) {
 			struct strbuf head = STRBUF_INIT;
-			strbuf_addstr(&head, src_ref_prefix);
+			strbuf_addstr(&head, "refs/heads/");
 			strbuf_addstr(&head, option_branch);
 			our_head_points_at =
 				find_ref_by_name(mapped_refs, head.buf);
@@ -763,7 +763,8 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 			      reflog_msg.buf);
 	}
 
-	if (our_head_points_at) {
+	if (our_head_points_at &&
+	    !prefixcmp(our_head_points_at->name, "refs/heads/")) {
 		/* Local default branch link */
 		create_symref("HEAD", our_head_points_at->name, NULL);
 		if (!option_bare) {

Documentation/git-clone.txt, builtin/clone.c, t/t5601-clone.sh

diff --git a/Documentation/git-clone.txt b/Documentation/git-clone.txt
index 4b8b26b..db2b29c 100644
--- a/Documentation/git-clone.txt
+++ b/Documentation/git-clone.txt
@@ -146,8 +146,9 @@ objects from the source repository into a pack in the cloned repository.
 -b <name>::
 	Instead of pointing the newly created HEAD to the branch pointed
 	to by the cloned repository's HEAD, point to `<name>` branch
-	instead. In a non-bare repository, this is the branch that will
-	be checked out.
+	instead. `--branch` can also take tags and treat them like
+	detached HEAD. In a non-bare repository, this is the branch
+	that will be checked out.
 
 --upload-pack <upload-pack>::
 -u <upload-pack>::
diff --git a/builtin/clone.c b/builtin/clone.c
index 914fd6b..0d4b9ab 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -734,6 +734,14 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 			strbuf_release(&head);
 
 			if (!our_head_points_at) {
+				strbuf_addstr(&head, "refs/tags/");
+				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);
@@ -776,6 +784,12 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 			install_branch_config(0, head, option_origin,
 					      our_head_points_at->name);
 		}
+	} else if (our_head_points_at) {
+		const struct ref *ref = our_head_points_at;
+		struct commit *c = lookup_commit_reference(ref->old_sha1);
+		/* Source had detached HEAD pointing somewhere. */
+		update_ref(reflog_msg.buf, "HEAD", c->object.sha1,
+			   NULL, REF_NODEREF, DIE_ON_ERR);
 	} else if (remote_head) {
 		/* Source had detached HEAD pointing somewhere. */
 		update_ref(reflog_msg.buf, "HEAD", remote_head->old_sha1,
diff --git a/t/t5601-clone.sh b/t/t5601-clone.sh
index e0b8db6..67869b4 100755
--- a/t/t5601-clone.sh
+++ b/t/t5601-clone.sh
@@ -271,4 +271,13 @@ test_expect_success 'clone from original with relative alternate' '
 	grep /src/\\.git/objects target-10/objects/info/alternates
 '
 
+test_expect_success 'clone checking out a tag' '
+	git clone --branch=some-tag src dst.tag &&
+	GIT_DIR=src/.git git rev-parse some-tag >expected &&
+	test_cmp expected dst.tag/.git/HEAD &&
+	GIT_DIR=dst.tag/.git git config remote.origin.fetch >fetch.actual &&
+	echo "+refs/heads/*:refs/remotes/origin/*" >fetch.expected &&
+	test_cmp fetch.expected fetch.actual
+'
+
 test_done

advice.c, advice.h, builtin/checkout.c, builtin/clone.c

diff --git a/advice.c b/advice.c
index e02e632..3e1a145 100644
--- a/advice.c
+++ b/advice.c
@@ -64,3 +64,17 @@ void NORETURN die_resolve_conflict(const char *me)
 	error_resolve_conflict(me);
 	die("Exiting because of an unresolved conflict.");
 }
+
+void detach_advice(const char *new_name)
+{
+	const char fmt[] =
+	"Note: checking out '%s'.\n\n"
+	"You are in 'detached HEAD' state. You can look around, make experimental\n"
+	"changes and commit them, and you can discard any commits you make in this\n"
+	"state without impacting any branches by performing another checkout.\n\n"
+	"If you want to create a new branch to retain commits you create, you may\n"
+	"do so (now or later) by using -b with the checkout command again. Example:\n\n"
+	"  git checkout -b new_branch_name\n\n";
+
+	fprintf(stderr, fmt, new_name);
+}
diff --git a/advice.h b/advice.h
index e5d0af7..7bda45b 100644
--- a/advice.h
+++ b/advice.h
@@ -14,5 +14,6 @@ int git_default_advice_config(const char *var, const char *value);
 void advise(const char *advice, ...);
 int error_resolve_conflict(const char *me);
 extern void NORETURN die_resolve_conflict(const char *me);
+void detach_advice(const char *new_name);
 
 #endif /* ADVICE_H */
diff --git a/builtin/checkout.c b/builtin/checkout.c
index f1984d9..5bf96ba 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -514,20 +514,6 @@ static void report_tracking(struct branch_info *new)
 	strbuf_release(&sb);
 }
 
-static void detach_advice(const char *old_path, const char *new_name)
-{
-	const char fmt[] =
-	"Note: checking out '%s'.\n\n"
-	"You are in 'detached HEAD' state. You can look around, make experimental\n"
-	"changes and commit them, and you can discard any commits you make in this\n"
-	"state without impacting any branches by performing another checkout.\n\n"
-	"If you want to create a new branch to retain commits you create, you may\n"
-	"do so (now or later) by using -b with the checkout command again. Example:\n\n"
-	"  git checkout -b new_branch_name\n\n";
-
-	fprintf(stderr, fmt, new_name);
-}
-
 static void update_refs_for_switch(struct checkout_opts *opts,
 				   struct branch_info *old,
 				   struct branch_info *new)
@@ -575,7 +561,7 @@ static void update_refs_for_switch(struct checkout_opts *opts,
 			   REF_NODEREF, DIE_ON_ERR);
 		if (!opts->quiet) {
 			if (old->path && advice_detached_head)
-				detach_advice(old->path, new->name);
+				detach_advice(new->name);
 			describe_detached_head(_("HEAD is now at"), new->commit);
 		}
 	} else if (new->path) {	/* Switch branches. */
diff --git a/builtin/clone.c b/builtin/clone.c
index 0d4b9ab..52596db 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -467,7 +467,10 @@ static int checkout(void)
 			  "unable to checkout.\n"));
 		return 0;
 	}
-	if (strcmp(head, "HEAD")) {
+	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!"));
 	}

diff --git a/t/t5500-fetch-pack.sh b/t/t5500-fetch-pack.sh
index 7e85c71..c4e675f 100755
--- a/t/t5500-fetch-pack.sh
+++ b/t/t5500-fetch-pack.sh
@@ -283,10 +283,7 @@ test_expect_success 'clone shallow object count' '
 '
 
 test_expect_success 'clone shallow with nonexistent --branch' '
-	git clone --depth 1 --branch Z "file://$(pwd)/." shallow4 &&
-	GIT_DIR=shallow4/.git git rev-parse HEAD >actual &&
-	git rev-parse HEAD >expected &&
-	test_cmp expected actual
+	test_must_fail git clone --depth 1 --branch Z "file://$(pwd)/." shallow4
 '
 
 test_expect_success 'clone shallow with detached HEAD' '
-- 8< --

I'd rather remove the test, but removing something in a merge does not
sound wise.

Another cleaner approach is to combine the two clone series into
one. If you want to go this way, pick one as base, I'll rebase the
other on top and resend.

diff --git a/t/t5601-clone.sh b/t/t5601-clone.sh
index 87ee016..49821eb 100755
--- a/t/t5601-clone.sh
+++ b/t/t5601-clone.sh
@@ -9,9 +9,9 @@ test_expect_success setup '
 	rm -fr .git &&
 	test_create_repo src &&
 	(
-		cd src
-		>file
-		git add file
+		cd src &&
+		>file &&
+		git add file &&
 		git commit -m initial
 	)
 

builtin/clone.c, t/t5601-clone.sh

diff --git a/builtin/clone.c b/builtin/clone.c
index 9dcc5fe..91862f7 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -764,12 +764,9 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		}
 	} 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;
-		}
+		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)
diff --git a/t/t5601-clone.sh b/t/t5601-clone.sh
index 49821eb..e0b8db6 100755
--- a/t/t5601-clone.sh
+++ b/t/t5601-clone.sh
@@ -12,7 +12,10 @@ test_expect_success setup '
 		cd src &&
 		>file &&
 		git add file &&
-		git commit -m initial
+		git commit -m initial &&
+		echo 1 >file &&
+		git add file &&
+		git commit -m updated
 	)
 
 '
@@ -88,6 +91,26 @@ test_expect_success 'clone --mirror' '
 
 '
 
+test_expect_success 'clone --mirror with detached HEAD' '
+
+	( cd src && git checkout HEAD^ && git rev-parse HEAD >../expected ) &&
+	git clone --mirror src mirror.detached &&
+	( cd src && git checkout - ) &&
+	GIT_DIR=mirror.detached git rev-parse HEAD >actual &&
+	test_cmp expected actual
+
+'
+
+test_expect_success 'clone --bare with detached HEAD' '
+
+	( cd src && git checkout HEAD^ && git rev-parse HEAD >../expected ) &&
+	git clone --bare src bare.detached &&
+	( cd src && git checkout - ) &&
+	GIT_DIR=bare.detached git rev-parse HEAD >actual &&
+	test_cmp expected actual
+
+'
+
 test_expect_success 'clone --bare names the local repository <name>.git' '
 
 	git clone --bare src &&

diff --git a/builtin/clone.c b/builtin/clone.c
index 91862f7..98e3542 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -486,6 +486,63 @@ static void write_followtags(const struct ref *refs, const char *msg)
 	}
 }
 
+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 (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);
@@ -766,13 +823,6 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		/* Source had detached HEAD pointing somewhere. */
 		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) {
@@ -780,42 +830,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		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_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);
-	}
+	err = checkout();
 
 	strbuf_release(&reflog_msg);
 	strbuf_release(&branch_top);

diff --git a/builtin/clone.c b/builtin/clone.c
index 98e3542..3b68014 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -486,6 +486,29 @@ static void write_followtags(const struct ref *refs, const char *msg)
 	}
 }
 
+static void update_head(const struct ref *our, const struct ref *remote,
+			const char *msg)
+{
+	if (our) {
+		/* 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 (remote) {
+		/*
+		 * We know remote HEAD points to a non-branch, or
+		 * HEAD points to a branch but we don't know which one, or
+		 * we asked for a specific branch but it did not exist.
+		 * 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];
@@ -807,23 +830,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 			      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. */
-		update_ref(reflog_msg.buf, "HEAD", remote_head->old_sha1,
-			   NULL, REF_NODEREF, DIE_ON_ERR);
-	}
+	update_head(our_head_points_at, remote_head, reflog_msg.buf);
 
 	if (transport) {
 		transport_unlock_pack(transport);

diff --git a/builtin/clone.c b/builtin/clone.c
index 3b68014..2733fa4 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -486,6 +486,29 @@ static void write_followtags(const struct ref *refs, const char *msg)
 	}
 }
 
+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) {
+		clear_extra_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)
 {
@@ -782,12 +805,6 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	}
 
 	if (refs) {
-		clear_extra_refs();
-
-		write_remote_refs(mapped_refs);
-		if (option_single_branch)
-			write_followtags(refs, reflog_msg.buf);
-
 		remote_head = find_ref_by_name(refs, "HEAD");
 		remote_head_points_at =
 			guess_remote_head(remote_head, mapped_refs, 0);
@@ -821,14 +838,8 @@ 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);
-	}
+	update_remote_refs(refs, mapped_refs, remote_head_points_at,
+			   branch_top.buf, reflog_msg.buf);
 
 	update_head(our_head_points_at, remote_head, reflog_msg.buf);
 

builtin/clone.c, transport.c

diff --git a/builtin/clone.c b/builtin/clone.c
index 2733fa4..a1fbb3b 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -364,13 +364,8 @@ 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 remote *remote;
-	struct transport *transport;
-
 	if (option_shared) {
 		struct strbuf alt = STRBUF_INIT;
 		strbuf_addf(&alt, "%s/objects", src_repo);
@@ -386,13 +381,8 @@ static const struct ref *clone_local(const char *src_repo,
 		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;
@@ -619,6 +609,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	struct strbuf key = STRBUF_INIT, value = STRBUF_INIT;
 	struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
 	struct transport *transport = NULL;
+	struct remote *remote;
 	int err = 0;
 
 	struct refspec *refspec;
@@ -773,13 +764,10 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 
 	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);
 
@@ -796,14 +784,23 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		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);
+	mapped_refs = refs ? wanted_peer_refs(refs, refspec) : NULL;
+
+	/*
+	 * mapped_refs may be updated if transport-helper is used so
+	 * 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.
+	 */
+	if (!is_local && remote->foreign_vcs && refs)
+		transport_fetch_refs(transport, mapped_refs);
+
 	if (refs) {
 		remote_head = find_ref_by_name(refs, "HEAD");
 		remote_head_points_at =
@@ -838,15 +835,18 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 					      "refs/heads/master");
 	}
 
+	if (is_local)
+		clone_local(path, git_dir);
+	else if (refs && !remote->foreign_vcs)
+		transport_fetch_refs(transport, mapped_refs);
+
 	update_remote_refs(refs, mapped_refs, remote_head_points_at,
 			   branch_top.buf, reflog_msg.buf);
 
 	update_head(our_head_points_at, remote_head, reflog_msg.buf);
 
-	if (transport) {
-		transport_unlock_pack(transport);
-		transport_disconnect(transport);
-	}
+	transport_unlock_pack(transport);
+	transport_disconnect(transport);
 
 	err = checkout();
 
diff --git a/transport.c b/transport.c
index a99b7c9..4366639 100644
--- a/transport.c
+++ b/transport.c
@@ -895,8 +895,10 @@ struct transport *transport_get(struct remote *remote, const char *url)
 
 		while (is_urlschemechar(p == url, *p))
 			p++;
-		if (!prefixcmp(p, "::"))
+		if (!prefixcmp(p, "::")) {
 			helper = xstrndup(url, p - url);
+			remote->foreign_vcs = helper;
+		}
 	}
 
 	if (helper) {
@@ -938,6 +940,7 @@ struct transport *transport_get(struct remote *remote, const char *url)
 		char *handler = xmalloc(len + 1);
 		handler[len] = 0;
 		strncpy(handler, url, len);
+		remote->foreign_vcs = handler;
 		transport_helper_init(ret, handler);
 	}
 

diff --git a/builtin/clone.c b/builtin/clone.c
index a1fbb3b..253a794 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -48,7 +48,6 @@ static int option_verbosity;
 static int option_progress;
 static struct string_list option_config;
 static struct string_list option_reference;
-static const char *src_ref_prefix = "refs/heads/";
 
 static int opt_parse_reference(const struct option *opt, const char *arg, int unset)
 {
@@ -413,6 +412,17 @@ 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);
+	return ref;
+}
+
 static struct ref *wanted_peer_refs(const struct ref *refs,
 		struct refspec *refspec)
 {
@@ -425,13 +435,8 @@ static struct ref *wanted_peer_refs(const struct ref *refs,
 
 		if (!option_branch)
 			remote_head = guess_remote_head(head, refs, 0);
-		else {
-			struct strbuf sb = STRBUF_INIT;
-			strbuf_addstr(&sb, src_ref_prefix);
-			strbuf_addstr(&sb, option_branch);
-			remote_head = find_ref_by_name(refs, sb.buf);
-			strbuf_release(&sb);
-		}
+		else
+			remote_head = find_remote_branch(refs, option_branch);
 
 		if (!remote_head && option_branch)
 			warning(_("Could not find remote branch %s to clone."),
@@ -502,7 +507,7 @@ static void update_remote_refs(const struct ref *refs,
 static void update_head(const struct ref *our, const struct ref *remote,
 			const char *msg)
 {
-	if (our) {
+	if (our && !prefixcmp(our->name, "refs/heads/")) {
 		/* Local default branch link */
 		create_symref("HEAD", our->name, NULL);
 		if (!option_bare) {
@@ -609,6 +614,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	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;
 
@@ -807,12 +813,8 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 			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);
+				find_remote_branch(mapped_refs, option_branch);
 
 			if (!our_head_points_at) {
 				warning(_("Remote branch %s not found in "

builtin/clone.c, t/t5500-fetch-pack.sh, t/t5706-clone-branch.sh

diff --git a/builtin/clone.c b/builtin/clone.c
index 253a794..3cfedb3 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -518,8 +518,7 @@ static void update_head(const struct ref *our, const struct ref *remote,
 	} 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, or
-		 * we asked for a specific branch but it did not exist.
+		 * 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,
@@ -816,12 +815,9 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 			our_head_points_at =
 				find_remote_branch(mapped_refs, option_branch);
 
-			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;
-			}
+			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;
diff --git a/t/t5500-fetch-pack.sh b/t/t5500-fetch-pack.sh
index 7e85c71..5237066 100755
--- a/t/t5500-fetch-pack.sh
+++ b/t/t5500-fetch-pack.sh
@@ -282,13 +282,6 @@ test_expect_success 'clone shallow object count' '
 	test_cmp count3.expected count3.actual
 '
 
-test_expect_success 'clone shallow with nonexistent --branch' '
-	git clone --depth 1 --branch Z "file://$(pwd)/." shallow4 &&
-	GIT_DIR=shallow4/.git git rev-parse HEAD >actual &&
-	git rev-parse HEAD >expected &&
-	test_cmp expected actual
-'
-
 test_expect_success 'clone shallow with detached HEAD' '
 	git checkout HEAD^ &&
 	git clone --depth 1 "file://$(pwd)/." shallow5 &&
diff --git a/t/t5706-clone-branch.sh b/t/t5706-clone-branch.sh
index f3f9a76..56be67e 100755
--- a/t/t5706-clone-branch.sh
+++ b/t/t5706-clone-branch.sh
@@ -57,12 +57,8 @@ test_expect_success 'clone -b does not munge remotes/origin/HEAD' '
 	)
 '
 
-test_expect_success 'clone -b with bogus branch chooses HEAD' '
-	git clone -b bogus parent clone-bogus &&
-	(cd clone-bogus &&
-	 check_HEAD master &&
-	 check_file one
-	)
+test_expect_success 'clone -b with bogus branch' '
+	test_must_fail git clone -b bogus parent clone-bogus
 '
 
 test_done

Documentation/git-clone.txt, builtin/clone.c, t/t5500-fetch-pack.sh, t/t5601-clone.sh

diff --git a/Documentation/git-clone.txt b/Documentation/git-clone.txt
index 0931a3e..6e22522 100644
--- a/Documentation/git-clone.txt
+++ b/Documentation/git-clone.txt
@@ -147,8 +147,9 @@ objects from the source repository into a pack in the cloned repository.
 -b <name>::
 	Instead of pointing the newly created HEAD to the branch pointed
 	to by the cloned repository's HEAD, point to `<name>` branch
-	instead. In a non-bare repository, this is the branch that will
-	be checked out.
+	instead. `--branch` can also take tags and treat them like
+	detached HEAD. In a non-bare repository, this is the branch
+	that will be checked out.
 
 --upload-pack <upload-pack>::
 -u <upload-pack>::
diff --git a/builtin/clone.c b/builtin/clone.c
index 3cfedb3..651b4cc 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -420,6 +420,15 @@ static struct ref *find_remote_branch(const struct ref *refs, const char *branch
 	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;
 }
 
@@ -441,8 +450,12 @@ static struct ref *wanted_peer_refs(const struct ref *refs,
 		if (!remote_head && option_branch)
 			warning(_("Could not find remote branch %s to clone."),
 				option_branch);
-		else
+		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);
 
@@ -515,6 +528,11 @@ static void update_head(const struct ref *our, const struct ref *remote,
 			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
diff --git a/t/t5500-fetch-pack.sh b/t/t5500-fetch-pack.sh
index 5237066..ce51692 100755
--- a/t/t5500-fetch-pack.sh
+++ b/t/t5500-fetch-pack.sh
@@ -311,4 +311,19 @@ EOF
 	test_cmp count6.expected count6.actual
 '
 
+test_expect_success 'shallow cloning single tag' '
+	git clone --depth 1 --branch=TAGB1 "file://$(pwd)/." shallow7 &&
+	cat >taglist.expected <<\EOF &&
+TAGB1
+TAGB2
+EOF
+	GIT_DIR=shallow7/.git git tag -l >taglist.actual &&
+	test_cmp taglist.expected taglist.actual &&
+
+	echo "in-pack: 7" > count7.expected &&
+	GIT_DIR=shallow7/.git git count-objects -v |
+		grep "^in-pack" > count7.actual &&
+	test_cmp count7.expected count7.actual
+'
+
 test_done
diff --git a/t/t5601-clone.sh b/t/t5601-clone.sh
index e0b8db6..67869b4 100755
--- a/t/t5601-clone.sh
+++ b/t/t5601-clone.sh
@@ -271,4 +271,13 @@ test_expect_success 'clone from original with relative alternate' '
 	grep /src/\\.git/objects target-10/objects/info/alternates
 '
 
+test_expect_success 'clone checking out a tag' '
+	git clone --branch=some-tag src dst.tag &&
+	GIT_DIR=src/.git git rev-parse some-tag >expected &&
+	test_cmp expected dst.tag/.git/HEAD &&
+	GIT_DIR=dst.tag/.git git config remote.origin.fetch >fetch.actual &&
+	echo "+refs/heads/*:refs/remotes/origin/*" >fetch.expected &&
+	test_cmp fetch.expected fetch.actual
+'
+
 test_done

advice.c, advice.h, builtin/checkout.c, builtin/clone.c

diff --git a/advice.c b/advice.c
index e02e632..3e1a145 100644
--- a/advice.c
+++ b/advice.c
@@ -64,3 +64,17 @@ void NORETURN die_resolve_conflict(const char *me)
 	error_resolve_conflict(me);
 	die("Exiting because of an unresolved conflict.");
 }
+
+void detach_advice(const char *new_name)
+{
+	const char fmt[] =
+	"Note: checking out '%s'.\n\n"
+	"You are in 'detached HEAD' state. You can look around, make experimental\n"
+	"changes and commit them, and you can discard any commits you make in this\n"
+	"state without impacting any branches by performing another checkout.\n\n"
+	"If you want to create a new branch to retain commits you create, you may\n"
+	"do so (now or later) by using -b with the checkout command again. Example:\n\n"
+	"  git checkout -b new_branch_name\n\n";
+
+	fprintf(stderr, fmt, new_name);
+}
diff --git a/advice.h b/advice.h
index e5d0af7..7bda45b 100644
--- a/advice.h
+++ b/advice.h
@@ -14,5 +14,6 @@ int git_default_advice_config(const char *var, const char *value);
 void advise(const char *advice, ...);
 int error_resolve_conflict(const char *me);
 extern void NORETURN die_resolve_conflict(const char *me);
+void detach_advice(const char *new_name);
 
 #endif /* ADVICE_H */
diff --git a/builtin/checkout.c b/builtin/checkout.c
index f1984d9..5bf96ba 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -514,20 +514,6 @@ static void report_tracking(struct branch_info *new)
 	strbuf_release(&sb);
 }
 
-static void detach_advice(const char *old_path, const char *new_name)
-{
-	const char fmt[] =
-	"Note: checking out '%s'.\n\n"
-	"You are in 'detached HEAD' state. You can look around, make experimental\n"
-	"changes and commit them, and you can discard any commits you make in this\n"
-	"state without impacting any branches by performing another checkout.\n\n"
-	"If you want to create a new branch to retain commits you create, you may\n"
-	"do so (now or later) by using -b with the checkout command again. Example:\n\n"
-	"  git checkout -b new_branch_name\n\n";
-
-	fprintf(stderr, fmt, new_name);
-}
-
 static void update_refs_for_switch(struct checkout_opts *opts,
 				   struct branch_info *old,
 				   struct branch_info *new)
@@ -575,7 +561,7 @@ static void update_refs_for_switch(struct checkout_opts *opts,
 			   REF_NODEREF, DIE_ON_ERR);
 		if (!opts->quiet) {
 			if (old->path && advice_detached_head)
-				detach_advice(old->path, new->name);
+				detach_advice(new->name);
 			describe_detached_head(_("HEAD is now at"), new->commit);
 		}
 	} else if (new->path) {	/* Switch branches. */
diff --git a/builtin/clone.c b/builtin/clone.c
index 651b4cc..72eebca 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -563,7 +563,10 @@ static int checkout(void)
 			  "unable to checkout.\n"));
 		return 0;
 	}
-	if (strcmp(head, "HEAD")) {
+	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!"));
 	}

diff --git a/t/t5601-clone.sh b/t/t5601-clone.sh
index 87ee016..49821eb 100755
--- a/t/t5601-clone.sh
+++ b/t/t5601-clone.sh
@@ -9,9 +9,9 @@ test_expect_success setup '
 	rm -fr .git &&
 	test_create_repo src &&
 	(
-		cd src
-		>file
-		git add file
+		cd src &&
+		>file &&
+		git add file &&
 		git commit -m initial
 	)
 

builtin/clone.c, t/t5601-clone.sh

diff --git a/builtin/clone.c b/builtin/clone.c
index 86db954..8dde1ea 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -720,12 +720,9 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		}
 	} 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;
-		}
+		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)
diff --git a/t/t5601-clone.sh b/t/t5601-clone.sh
index 49821eb..e0b8db6 100755
--- a/t/t5601-clone.sh
+++ b/t/t5601-clone.sh
@@ -12,7 +12,10 @@ test_expect_success setup '
 		cd src &&
 		>file &&
 		git add file &&
-		git commit -m initial
+		git commit -m initial &&
+		echo 1 >file &&
+		git add file &&
+		git commit -m updated
 	)
 
 '
@@ -88,6 +91,26 @@ test_expect_success 'clone --mirror' '
 
 '
 
+test_expect_success 'clone --mirror with detached HEAD' '
+
+	( cd src && git checkout HEAD^ && git rev-parse HEAD >../expected ) &&
+	git clone --mirror src mirror.detached &&
+	( cd src && git checkout - ) &&
+	GIT_DIR=mirror.detached git rev-parse HEAD >actual &&
+	test_cmp expected actual
+
+'
+
+test_expect_success 'clone --bare with detached HEAD' '
+
+	( cd src && git checkout HEAD^ && git rev-parse HEAD >../expected ) &&
+	git clone --bare src bare.detached &&
+	( cd src && git checkout - ) &&
+	GIT_DIR=bare.detached git rev-parse HEAD >actual &&
+	test_cmp expected actual
+
+'
+
 test_expect_success 'clone --bare names the local repository <name>.git' '
 
 	git clone --bare src &&

diff --git a/builtin/clone.c b/builtin/clone.c
index 8dde1ea..100056d 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -448,6 +448,63 @@ static void write_remote_refs(const struct ref *local_refs)
 	clear_extra_refs();
 }
 
+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 (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);
@@ -722,13 +779,6 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		/* Source had detached HEAD pointing somewhere. */
 		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) {
@@ -736,42 +786,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		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_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);
-	}
+	err = checkout();
 
 	strbuf_release(&reflog_msg);
 	strbuf_release(&branch_top);

diff --git a/builtin/clone.c b/builtin/clone.c
index 100056d..baed5ae 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -448,6 +448,29 @@ static void write_remote_refs(const struct ref *local_refs)
 	clear_extra_refs();
 }
 
+static void update_head(const struct ref *our, const struct ref *remote,
+			const char *msg)
+{
+	if (our) {
+		/* 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 (remote) {
+		/*
+		 * We know remote HEAD points to a non-branch, or
+		 * HEAD points to a branch but we don't know which one, or
+		 * we asked for a specific branch but it did not exist.
+		 * 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];
@@ -763,23 +786,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 			      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. */
-		update_ref(reflog_msg.buf, "HEAD", remote_head->old_sha1,
-			   NULL, REF_NODEREF, DIE_ON_ERR);
-	}
+	update_head(our_head_points_at, remote_head, reflog_msg.buf);
 
 	if (transport) {
 		transport_unlock_pack(transport);

diff --git a/builtin/clone.c b/builtin/clone.c
index baed5ae..d1d6dca 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -448,6 +448,28 @@ static void write_remote_refs(const struct ref *local_refs)
 	clear_extra_refs();
 }
 
+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) {
+		clear_extra_refs();
+		write_remote_refs(mapped_refs);
+	}
+
+	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)
 {
@@ -740,10 +762,6 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	}
 
 	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);
@@ -777,14 +795,8 @@ 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);
-	}
+	update_remote_refs(refs, mapped_refs, remote_head_points_at,
+			   branch_top.buf, reflog_msg.buf);
 
 	update_head(our_head_points_at, remote_head, reflog_msg.buf);
 

builtin/clone.c, transport.c

diff --git a/builtin/clone.c b/builtin/clone.c
index d1d6dca..a9d06a4 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -361,13 +361,8 @@ 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 remote *remote;
-	struct transport *transport;
-
 	if (option_shared) {
 		struct strbuf alt = STRBUF_INIT;
 		strbuf_addf(&alt, "%s/objects", src_repo);
@@ -383,13 +378,8 @@ static const struct ref *clone_local(const char *src_repo,
 		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;
@@ -581,6 +571,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
 	struct transport *transport = NULL;
 	char *src_ref_prefix = "refs/heads/";
+	struct remote *remote;
 	int err = 0;
 
 	struct refspec *refspec;
@@ -732,13 +723,10 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 
 	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);
 
@@ -753,14 +741,23 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		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);
+	mapped_refs = refs ? wanted_peer_refs(refs, refspec) : NULL;
+
+	/*
+	 * mapped_refs may be updated if transport-helper is used so
+	 * 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.
+	 */
+	if (!is_local && remote->foreign_vcs && refs)
+		transport_fetch_refs(transport, mapped_refs);
+
 	if (refs) {
 		remote_head = find_ref_by_name(refs, "HEAD");
 		remote_head_points_at =
@@ -795,15 +792,18 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 					      "refs/heads/master");
 	}
 
+	if (is_local)
+		clone_local(path, git_dir);
+	else if (refs && !remote->foreign_vcs)
+		transport_fetch_refs(transport, mapped_refs);
+
 	update_remote_refs(refs, mapped_refs, remote_head_points_at,
 			   branch_top.buf, reflog_msg.buf);
 
 	update_head(our_head_points_at, remote_head, reflog_msg.buf);
 
-	if (transport) {
-		transport_unlock_pack(transport);
-		transport_disconnect(transport);
-	}
+	transport_unlock_pack(transport);
+	transport_disconnect(transport);
 
 	err = checkout();
 
diff --git a/transport.c b/transport.c
index a99b7c9..4366639 100644
--- a/transport.c
+++ b/transport.c
@@ -895,8 +895,10 @@ struct transport *transport_get(struct remote *remote, const char *url)
 
 		while (is_urlschemechar(p == url, *p))
 			p++;
-		if (!prefixcmp(p, "::"))
+		if (!prefixcmp(p, "::")) {
 			helper = xstrndup(url, p - url);
+			remote->foreign_vcs = helper;
+		}
 	}
 
 	if (helper) {
@@ -938,6 +940,7 @@ struct transport *transport_get(struct remote *remote, const char *url)
 		char *handler = xmalloc(len + 1);
 		handler[len] = 0;
 		strncpy(handler, url, len);
+		remote->foreign_vcs = handler;
 		transport_helper_init(ret, handler);
 	}
 

diff --git a/builtin/clone.c b/builtin/clone.c
index a9d06a4..89ba6f0 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -463,7 +463,7 @@ static void update_remote_refs(const struct ref *refs,
 static void update_head(const struct ref *our, const struct ref *remote,
 			const char *msg)
 {
-	if (our) {
+	if (our && !prefixcmp(our->name, "refs/heads/")) {
 		/* Local default branch link */
 		create_symref("HEAD", our->name, NULL);
 		if (!option_bare) {
@@ -765,7 +765,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 
 		if (option_branch) {
 			struct strbuf head = STRBUF_INIT;
-			strbuf_addstr(&head, src_ref_prefix);
+			strbuf_addstr(&head, "refs/heads/");
 			strbuf_addstr(&head, option_branch);
 			our_head_points_at =
 				find_ref_by_name(mapped_refs, head.buf);

builtin/clone.c, t/t5706-clone-branch.sh

diff --git a/builtin/clone.c b/builtin/clone.c
index 89ba6f0..6a2886a 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -474,8 +474,7 @@ static void update_head(const struct ref *our, const struct ref *remote,
 	} 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, or
-		 * we asked for a specific branch but it did not exist.
+		 * 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,
@@ -771,12 +770,10 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 				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;
-			}
+			if (!our_head_points_at)
+				die(_("Remote branch %s not found in "
+				      "upstream %s, using HEAD instead"),
+				    option_branch, option_origin);
 		}
 		else
 			our_head_points_at = remote_head_points_at;
diff --git a/t/t5706-clone-branch.sh b/t/t5706-clone-branch.sh
index f3f9a76..56be67e 100755
--- a/t/t5706-clone-branch.sh
+++ b/t/t5706-clone-branch.sh
@@ -57,12 +57,8 @@ test_expect_success 'clone -b does not munge remotes/origin/HEAD' '
 	)
 '
 
-test_expect_success 'clone -b with bogus branch chooses HEAD' '
-	git clone -b bogus parent clone-bogus &&
-	(cd clone-bogus &&
-	 check_HEAD master &&
-	 check_file one
-	)
+test_expect_success 'clone -b with bogus branch' '
+	test_must_fail git clone -b bogus parent clone-bogus
 '
 
 test_done

Documentation/git-clone.txt, builtin/clone.c, t/t5601-clone.sh

diff --git a/Documentation/git-clone.txt b/Documentation/git-clone.txt
index 4b8b26b..db2b29c 100644
--- a/Documentation/git-clone.txt
+++ b/Documentation/git-clone.txt
@@ -146,8 +146,9 @@ objects from the source repository into a pack in the cloned repository.
 -b <name>::
 	Instead of pointing the newly created HEAD to the branch pointed
 	to by the cloned repository's HEAD, point to `<name>` branch
-	instead. In a non-bare repository, this is the branch that will
-	be checked out.
+	instead. `--branch` can also take tags and treat them like
+	detached HEAD. In a non-bare repository, this is the branch
+	that will be checked out.
 
 --upload-pack <upload-pack>::
 -u <upload-pack>::
diff --git a/builtin/clone.c b/builtin/clone.c
index 6a2886a..a3c8f78 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -471,6 +471,11 @@ static void update_head(const struct ref *our, const struct ref *remote,
 			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
@@ -770,6 +775,14 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 				find_ref_by_name(mapped_refs, head.buf);
 			strbuf_release(&head);
 
+			if (!our_head_points_at) {
+				strbuf_addstr(&head, "refs/tags/");
+				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)
 				die(_("Remote branch %s not found in "
 				      "upstream %s, using HEAD instead"),
diff --git a/t/t5601-clone.sh b/t/t5601-clone.sh
index e0b8db6..67869b4 100755
--- a/t/t5601-clone.sh
+++ b/t/t5601-clone.sh
@@ -271,4 +271,13 @@ test_expect_success 'clone from original with relative alternate' '
 	grep /src/\\.git/objects target-10/objects/info/alternates
 '
 
+test_expect_success 'clone checking out a tag' '
+	git clone --branch=some-tag src dst.tag &&
+	GIT_DIR=src/.git git rev-parse some-tag >expected &&
+	test_cmp expected dst.tag/.git/HEAD &&
+	GIT_DIR=dst.tag/.git git config remote.origin.fetch >fetch.actual &&
+	echo "+refs/heads/*:refs/remotes/origin/*" >fetch.expected &&
+	test_cmp fetch.expected fetch.actual
+'
+
 test_done

advice.c, advice.h, builtin/checkout.c, builtin/clone.c

diff --git a/advice.c b/advice.c
index e02e632..3e1a145 100644
--- a/advice.c
+++ b/advice.c
@@ -64,3 +64,17 @@ void NORETURN die_resolve_conflict(const char *me)
 	error_resolve_conflict(me);
 	die("Exiting because of an unresolved conflict.");
 }
+
+void detach_advice(const char *new_name)
+{
+	const char fmt[] =
+	"Note: checking out '%s'.\n\n"
+	"You are in 'detached HEAD' state. You can look around, make experimental\n"
+	"changes and commit them, and you can discard any commits you make in this\n"
+	"state without impacting any branches by performing another checkout.\n\n"
+	"If you want to create a new branch to retain commits you create, you may\n"
+	"do so (now or later) by using -b with the checkout command again. Example:\n\n"
+	"  git checkout -b new_branch_name\n\n";
+
+	fprintf(stderr, fmt, new_name);
+}
diff --git a/advice.h b/advice.h
index e5d0af7..7bda45b 100644
--- a/advice.h
+++ b/advice.h
@@ -14,5 +14,6 @@ int git_default_advice_config(const char *var, const char *value);
 void advise(const char *advice, ...);
 int error_resolve_conflict(const char *me);
 extern void NORETURN die_resolve_conflict(const char *me);
+void detach_advice(const char *new_name);
 
 #endif /* ADVICE_H */
diff --git a/builtin/checkout.c b/builtin/checkout.c
index f1984d9..5bf96ba 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -514,20 +514,6 @@ static void report_tracking(struct branch_info *new)
 	strbuf_release(&sb);
 }
 
-static void detach_advice(const char *old_path, const char *new_name)
-{
-	const char fmt[] =
-	"Note: checking out '%s'.\n\n"
-	"You are in 'detached HEAD' state. You can look around, make experimental\n"
-	"changes and commit them, and you can discard any commits you make in this\n"
-	"state without impacting any branches by performing another checkout.\n\n"
-	"If you want to create a new branch to retain commits you create, you may\n"
-	"do so (now or later) by using -b with the checkout command again. Example:\n\n"
-	"  git checkout -b new_branch_name\n\n";
-
-	fprintf(stderr, fmt, new_name);
-}
-
 static void update_refs_for_switch(struct checkout_opts *opts,
 				   struct branch_info *old,
 				   struct branch_info *new)
@@ -575,7 +561,7 @@ static void update_refs_for_switch(struct checkout_opts *opts,
 			   REF_NODEREF, DIE_ON_ERR);
 		if (!opts->quiet) {
 			if (old->path && advice_detached_head)
-				detach_advice(old->path, new->name);
+				detach_advice(new->name);
 			describe_detached_head(_("HEAD is now at"), new->commit);
 		}
 	} else if (new->path) {	/* Switch branches. */
diff --git a/builtin/clone.c b/builtin/clone.c
index a3c8f78..bfdafaa 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -506,7 +506,10 @@ static int checkout(void)
 			  "unable to checkout.\n"));
 		return 0;
 	}
-	if (strcmp(head, "HEAD")) {
+	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!"));
 	}

diff --git a/t/t5601-clone.sh b/t/t5601-clone.sh
index 87ee016..49821eb 100755
--- a/t/t5601-clone.sh
+++ b/t/t5601-clone.sh
@@ -9,9 +9,9 @@ test_expect_success setup '
 	rm -fr .git &&
 	test_create_repo src &&
 	(
-		cd src
-		>file
-		git add file
+		cd src &&
+		>file &&
+		git add file &&
 		git commit -m initial
 	)
 

builtin/clone.c, t/t5601-clone.sh

diff --git a/builtin/clone.c b/builtin/clone.c
index 86db954..8dde1ea 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -720,12 +720,9 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		}
 	} 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;
-		}
+		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)
diff --git a/t/t5601-clone.sh b/t/t5601-clone.sh
index 49821eb..e0b8db6 100755
--- a/t/t5601-clone.sh
+++ b/t/t5601-clone.sh
@@ -12,7 +12,10 @@ test_expect_success setup '
 		cd src &&
 		>file &&
 		git add file &&
-		git commit -m initial
+		git commit -m initial &&
+		echo 1 >file &&
+		git add file &&
+		git commit -m updated
 	)
 
 '
@@ -88,6 +91,26 @@ test_expect_success 'clone --mirror' '
 
 '
 
+test_expect_success 'clone --mirror with detached HEAD' '
+
+	( cd src && git checkout HEAD^ && git rev-parse HEAD >../expected ) &&
+	git clone --mirror src mirror.detached &&
+	( cd src && git checkout - ) &&
+	GIT_DIR=mirror.detached git rev-parse HEAD >actual &&
+	test_cmp expected actual
+
+'
+
+test_expect_success 'clone --bare with detached HEAD' '
+
+	( cd src && git checkout HEAD^ && git rev-parse HEAD >../expected ) &&
+	git clone --bare src bare.detached &&
+	( cd src && git checkout - ) &&
+	GIT_DIR=bare.detached git rev-parse HEAD >actual &&
+	test_cmp expected actual
+
+'
+
 test_expect_success 'clone --bare names the local repository <name>.git' '
 
 	git clone --bare src &&

diff --git a/builtin/clone.c b/builtin/clone.c
index 8dde1ea..100056d 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -448,6 +448,63 @@ static void write_remote_refs(const struct ref *local_refs)
 	clear_extra_refs();
 }
 
+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 (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);
@@ -722,13 +779,6 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		/* Source had detached HEAD pointing somewhere. */
 		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) {
@@ -736,42 +786,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		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_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);
-	}
+	err = checkout();
 
 	strbuf_release(&reflog_msg);
 	strbuf_release(&branch_top);

diff --git a/builtin/clone.c b/builtin/clone.c
index 100056d..26a037c 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -448,6 +448,24 @@ static void write_remote_refs(const struct ref *local_refs)
 	clear_extra_refs();
 }
 
+static void update_head(const struct ref *our, const struct ref *remote,
+			const char *msg)
+{
+	if (our) {
+		/* 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 (remote) {
+		/* Source had detached HEAD pointing somewhere. */
+		update_ref(msg, "HEAD", remote->old_sha1,
+			   NULL, REF_NODEREF, DIE_ON_ERR);
+	}
+}
+
 static int checkout(void)
 {
 	unsigned char sha1[20];
@@ -763,23 +781,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 			      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. */
-		update_ref(reflog_msg.buf, "HEAD", remote_head->old_sha1,
-			   NULL, REF_NODEREF, DIE_ON_ERR);
-	}
+	update_head(our_head_points_at, remote_head, reflog_msg.buf);
 
 	if (transport) {
 		transport_unlock_pack(transport);

diff --git a/builtin/clone.c b/builtin/clone.c
index 26a037c..73d07ed 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -448,6 +448,28 @@ static void write_remote_refs(const struct ref *local_refs)
 	clear_extra_refs();
 }
 
+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) {
+		clear_extra_refs();
+		write_remote_refs(mapped_refs);
+	}
+
+	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)
 {
@@ -735,10 +757,6 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	}
 
 	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);
@@ -772,14 +790,8 @@ 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);
-	}
+	update_remote_refs(refs, mapped_refs, remote_head_points_at,
+			   branch_top.buf, reflog_msg.buf);
 
 	update_head(our_head_points_at, remote_head, reflog_msg.buf);
 

builtin/clone.c, transport.c

diff --git a/builtin/clone.c b/builtin/clone.c
index 73d07ed..05224d7 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -361,13 +361,8 @@ 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 remote *remote;
-	struct transport *transport;
-
 	if (option_shared) {
 		struct strbuf alt = STRBUF_INIT;
 		strbuf_addf(&alt, "%s/objects", src_repo);
@@ -383,13 +378,8 @@ static const struct ref *clone_local(const char *src_repo,
 		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;
@@ -576,6 +566,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
 	struct transport *transport = NULL;
 	char *src_ref_prefix = "refs/heads/";
+	struct remote *remote;
 	int err = 0;
 
 	struct refspec *refspec;
@@ -727,13 +718,10 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 
 	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);
 
@@ -748,14 +736,23 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		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);
+	mapped_refs = refs ? wanted_peer_refs(refs, refspec) : NULL;
+
+	/*
+	 * mapped_refs may be updated if transport-helper is used so
+	 * 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.
+	 */
+	if (!is_local && remote->foreign_vcs && refs)
+		transport_fetch_refs(transport, mapped_refs);
+
 	if (refs) {
 		remote_head = find_ref_by_name(refs, "HEAD");
 		remote_head_points_at =
@@ -790,15 +787,18 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 					      "refs/heads/master");
 	}
 
+	if (is_local)
+		clone_local(path, git_dir);
+	else if (refs && !remote->foreign_vcs)
+		transport_fetch_refs(transport, mapped_refs);
+
 	update_remote_refs(refs, mapped_refs, remote_head_points_at,
 			   branch_top.buf, reflog_msg.buf);
 
 	update_head(our_head_points_at, remote_head, reflog_msg.buf);
 
-	if (transport) {
-		transport_unlock_pack(transport);
-		transport_disconnect(transport);
-	}
+	transport_unlock_pack(transport);
+	transport_disconnect(transport);
 
 	err = checkout();
 
diff --git a/transport.c b/transport.c
index a99b7c9..aae9889 100644
--- a/transport.c
+++ b/transport.c
@@ -895,8 +895,10 @@ struct transport *transport_get(struct remote *remote, const char *url)
 
 		while (is_urlschemechar(p == url, *p))
 			p++;
-		if (!prefixcmp(p, "::"))
+		if (!prefixcmp(p, "::")) {
 			helper = xstrndup(url, p - url);
+			remote->foreign_vcs = helper;
+		}
 	}
 
 	if (helper) {
@@ -938,6 +940,7 @@ struct transport *transport_get(struct remote *remote, const char *url)
 		char *handler = xmalloc(len + 1);
 		handler[len] = 0;
 		strncpy(handler, url, len);
+		remote->foreign_vcs = helper;
 		transport_helper_init(ret, handler);
 	}
 

diff --git a/builtin/push.c b/builtin/push.c
index 35cce53..5fb98a0 100644
--- a/builtin/push.c
+++ b/builtin/push.c
@@ -204,11 +204,13 @@ static int do_push(const char *repo, int flags)
 		url_nr = remote->url_nr;
 	}
 	if (url_nr) {
+		const char *configured_foreign_vcs = remote->foreign_vcs;
 		for (i = 0; i < url_nr; i++) {
 			struct transport *transport =
 				transport_get(remote, url[i]);
 			if (push_with_options(transport, flags))
 				errs++;
+			remote->foreign_vcs = configured_foreign_vcs;
 		}
 	} else {
 		struct transport *transport =

diff --git a/builtin/clone.c b/builtin/clone.c
index 05224d7..960242f 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -463,7 +463,7 @@ static void update_remote_refs(const struct ref *refs,
 static void update_head(const struct ref *our, const struct ref *remote,
 			const char *msg)
 {
-	if (our) {
+	if (our && !prefixcmp(our->name, "refs/heads/")) {
 		/* Local default branch link */
 		create_symref("HEAD", our->name, NULL);
 		if (!option_bare) {
@@ -760,7 +760,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 
 		if (option_branch) {
 			struct strbuf head = STRBUF_INIT;
-			strbuf_addstr(&head, src_ref_prefix);
+			strbuf_addstr(&head, "refs/heads/");
 			strbuf_addstr(&head, option_branch);
 			our_head_points_at =
 				find_ref_by_name(mapped_refs, head.buf);

builtin/clone.c, t/t5706-clone-branch.sh

diff --git a/builtin/clone.c b/builtin/clone.c
index 960242f..f751997 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -766,12 +766,10 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 				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;
-			}
+			if (!our_head_points_at)
+				die(_("Remote branch %s not found in "
+				      "upstream %s, using HEAD instead"),
+				    option_branch, option_origin);
 		}
 		else
 			our_head_points_at = remote_head_points_at;
diff --git a/t/t5706-clone-branch.sh b/t/t5706-clone-branch.sh
index f3f9a76..56be67e 100755
--- a/t/t5706-clone-branch.sh
+++ b/t/t5706-clone-branch.sh
@@ -57,12 +57,8 @@ test_expect_success 'clone -b does not munge remotes/origin/HEAD' '
 	)
 '
 
-test_expect_success 'clone -b with bogus branch chooses HEAD' '
-	git clone -b bogus parent clone-bogus &&
-	(cd clone-bogus &&
-	 check_HEAD master &&
-	 check_file one
-	)
+test_expect_success 'clone -b with bogus branch' '
+	test_must_fail git clone -b bogus parent clone-bogus
 '
 
 test_done

Documentation/git-clone.txt, builtin/clone.c, t/t5601-clone.sh

diff --git a/Documentation/git-clone.txt b/Documentation/git-clone.txt
index 4b8b26b..db2b29c 100644
--- a/Documentation/git-clone.txt
+++ b/Documentation/git-clone.txt
@@ -146,8 +146,9 @@ objects from the source repository into a pack in the cloned repository.
 -b <name>::
 	Instead of pointing the newly created HEAD to the branch pointed
 	to by the cloned repository's HEAD, point to `<name>` branch
-	instead. In a non-bare repository, this is the branch that will
-	be checked out.
+	instead. `--branch` can also take tags and treat them like
+	detached HEAD. In a non-bare repository, this is the branch
+	that will be checked out.
 
 --upload-pack <upload-pack>::
 -u <upload-pack>::
diff --git a/builtin/clone.c b/builtin/clone.c
index f751997..ed18c1a 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -471,6 +471,11 @@ static void update_head(const struct ref *our, const struct ref *remote,
 			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);
+		/* Source had detached HEAD pointing somewhere. */
+		update_ref(msg, "HEAD", c->object.sha1,
+			   NULL, REF_NODEREF, DIE_ON_ERR);
 	} else if (remote) {
 		/* Source had detached HEAD pointing somewhere. */
 		update_ref(msg, "HEAD", remote->old_sha1,
@@ -766,6 +771,14 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 				find_ref_by_name(mapped_refs, head.buf);
 			strbuf_release(&head);
 
+			if (!our_head_points_at) {
+				strbuf_addstr(&head, "refs/tags/");
+				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)
 				die(_("Remote branch %s not found in "
 				      "upstream %s, using HEAD instead"),
diff --git a/t/t5601-clone.sh b/t/t5601-clone.sh
index e0b8db6..67869b4 100755
--- a/t/t5601-clone.sh
+++ b/t/t5601-clone.sh
@@ -271,4 +271,13 @@ test_expect_success 'clone from original with relative alternate' '
 	grep /src/\\.git/objects target-10/objects/info/alternates
 '
 
+test_expect_success 'clone checking out a tag' '
+	git clone --branch=some-tag src dst.tag &&
+	GIT_DIR=src/.git git rev-parse some-tag >expected &&
+	test_cmp expected dst.tag/.git/HEAD &&
+	GIT_DIR=dst.tag/.git git config remote.origin.fetch >fetch.actual &&
+	echo "+refs/heads/*:refs/remotes/origin/*" >fetch.expected &&
+	test_cmp fetch.expected fetch.actual
+'
+
 test_done

advice.c, advice.h, builtin/checkout.c, builtin/clone.c

diff --git a/advice.c b/advice.c
index e02e632..3e1a145 100644
--- a/advice.c
+++ b/advice.c
@@ -64,3 +64,17 @@ void NORETURN die_resolve_conflict(const char *me)
 	error_resolve_conflict(me);
 	die("Exiting because of an unresolved conflict.");
 }
+
+void detach_advice(const char *new_name)
+{
+	const char fmt[] =
+	"Note: checking out '%s'.\n\n"
+	"You are in 'detached HEAD' state. You can look around, make experimental\n"
+	"changes and commit them, and you can discard any commits you make in this\n"
+	"state without impacting any branches by performing another checkout.\n\n"
+	"If you want to create a new branch to retain commits you create, you may\n"
+	"do so (now or later) by using -b with the checkout command again. Example:\n\n"
+	"  git checkout -b new_branch_name\n\n";
+
+	fprintf(stderr, fmt, new_name);
+}
diff --git a/advice.h b/advice.h
index e5d0af7..7bda45b 100644
--- a/advice.h
+++ b/advice.h
@@ -14,5 +14,6 @@ int git_default_advice_config(const char *var, const char *value);
 void advise(const char *advice, ...);
 int error_resolve_conflict(const char *me);
 extern void NORETURN die_resolve_conflict(const char *me);
+void detach_advice(const char *new_name);
 
 #endif /* ADVICE_H */
diff --git a/builtin/checkout.c b/builtin/checkout.c
index f1984d9..5bf96ba 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -514,20 +514,6 @@ static void report_tracking(struct branch_info *new)
 	strbuf_release(&sb);
 }
 
-static void detach_advice(const char *old_path, const char *new_name)
-{
-	const char fmt[] =
-	"Note: checking out '%s'.\n\n"
-	"You are in 'detached HEAD' state. You can look around, make experimental\n"
-	"changes and commit them, and you can discard any commits you make in this\n"
-	"state without impacting any branches by performing another checkout.\n\n"
-	"If you want to create a new branch to retain commits you create, you may\n"
-	"do so (now or later) by using -b with the checkout command again. Example:\n\n"
-	"  git checkout -b new_branch_name\n\n";
-
-	fprintf(stderr, fmt, new_name);
-}
-
 static void update_refs_for_switch(struct checkout_opts *opts,
 				   struct branch_info *old,
 				   struct branch_info *new)
@@ -575,7 +561,7 @@ static void update_refs_for_switch(struct checkout_opts *opts,
 			   REF_NODEREF, DIE_ON_ERR);
 		if (!opts->quiet) {
 			if (old->path && advice_detached_head)
-				detach_advice(old->path, new->name);
+				detach_advice(new->name);
 			describe_detached_head(_("HEAD is now at"), new->commit);
 		}
 	} else if (new->path) {	/* Switch branches. */
diff --git a/builtin/clone.c b/builtin/clone.c
index ed18c1a..70f0280 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -502,7 +502,10 @@ static int checkout(void)
 			  "unable to checkout.\n"));
 		return 0;
 	}
-	if (strcmp(head, "HEAD")) {
+	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!"));
 	}