Merge branch 'jt/clone-unborn-head'

"git clone" tries to locally check out the branch pointed at by
HEAD of the remote repository after it is done, but the protocol
did not convey the information necessary to do so when copying an
empty repository.  The protocol v2 learned how to do so.

* jt/clone-unborn-head:
  clone: respect remote unborn HEAD
  connect, transport: encapsulate arg in struct
  ls-refs: report unborn targets of symrefs

1 files changed, 29 insertions, 3 deletions

diff --git a/connect.c b/connect.c
index 9c97fee430..40b5c15f81 100644
--- a/connect.c
+++ b/connect.c
@@ -376,7 +376,8 @@ struct ref **get_remote_heads(struct packet_reader *reader,
 }
 
 /* Returns 1 when a valid ref has been added to `list`, 0 otherwise */
-static int process_ref_v2(struct packet_reader *reader, struct ref ***list)
+static int process_ref_v2(struct packet_reader *reader, struct ref ***list,
+			  char **unborn_head_target)
 {
 	int ret = 1;
 	int i = 0;
@@ -397,6 +398,25 @@ static int process_ref_v2(struct packet_reader *reader, struct ref ***list)
 		goto out;
 	}
 
+	if (!strcmp("unborn", line_sections.items[i].string)) {
+		i++;
+		if (unborn_head_target &&
+		    !strcmp("HEAD", line_sections.items[i++].string)) {
+			/*
+			 * Look for the symref target (if any). If found,
+			 * return it to the caller.
+			 */
+			for (; i < line_sections.nr; i++) {
+				const char *arg = line_sections.items[i].string;
+
+				if (skip_prefix(arg, "symref-target:", &arg)) {
+					*unborn_head_target = xstrdup(arg);
+					break;
+				}
+			}
+		}
+		goto out;
+	}
 	if (parse_oid_hex_algop(line_sections.items[i++].string, &old_oid, &end, reader->hash_algo) ||
 	    *end) {
 		ret = 0;
@@ -453,12 +473,16 @@ void check_stateless_delimiter(int stateless_rpc,
 
 struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
 			     struct ref **list, int for_push,
-			     const struct strvec *ref_prefixes,
+			     struct transport_ls_refs_options *transport_options,
 			     const struct string_list *server_options,
 			     int stateless_rpc)
 {
 	int i;
 	const char *hash_name;
+	struct strvec *ref_prefixes = transport_options ?
+		&transport_options->ref_prefixes : NULL;
+	char **unborn_head_target = transport_options ?
+		&transport_options->unborn_head_target : NULL;
 	*list = NULL;
 
 	if (server_supports_v2("ls-refs", 1))
@@ -488,6 +512,8 @@ struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
 	if (!for_push)
 		packet_write_fmt(fd_out, "peel\n");
 	packet_write_fmt(fd_out, "symrefs\n");
+	if (server_supports_feature("ls-refs", "unborn", 0))
+		packet_write_fmt(fd_out, "unborn\n");
 	for (i = 0; ref_prefixes && i < ref_prefixes->nr; i++) {
 		packet_write_fmt(fd_out, "ref-prefix %s\n",
 				 ref_prefixes->v[i]);
@@ -496,7 +522,7 @@ struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
 
 	/* Process response from server */
 	while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
-		if (!process_ref_v2(reader, &list))
+		if (!process_ref_v2(reader, &list, unborn_head_target))
 			die(_("invalid ls-refs response: %s"), reader->line);
 	}