Merge branch 'bw/server-options'

The transport protocol v2 is getting updated further.

* bw/server-options:
  fetch: send server options when using protocol v2
  ls-remote: send server options when using protocol v2
  serve: introduce the server-option capability

Documentation/fetch-options.txt

@@ -188,6 +188,14 @@ endif::git-pull[]
 	is specified. This flag forces progress status even if the
 	standard error stream is not directed to a terminal.
 
+-o <option>::
+--server-option=<option>::
+	Transmit the given string to the server when communicating using
+	protocol version 2.  The given string must not contain a NUL or LF
+	character.
+	When multiple `--server-option=<option>` are given, they are all
+	sent to the other side in the order listed on the command line.
+
 -4::
 --ipv4::
 	Use IPv4 addresses only, ignoring IPv6 addresses.

Documentation/git-ls-remote.txt

@@ -70,6 +70,14 @@ OPTIONS
 	themselves will not work for refs whose objects have not yet been
 	fetched from the remote, and will give a `missing object` error.
 
+-o <option>::
+--server-option=<option>::
+	Transmit the given string to the server when communicating using
+	protocol version 2.  The given string must not contain a NUL or LF
+	character.
+	When multiple `--server-option=<option>` are given, they are all
+	sent to the other side in the order listed on the command line.
+
 <repository>::
 	The "remote" repository to query.  This parameter can be
 	either a URL or the name of a remote (see the GIT URLS and

Documentation/technical/protocol-v2.txt

@@ -393,3 +393,13 @@ header.
 		1 - pack data
 		2 - progress messages
 		3 - fatal error message just before stream aborts
+
+ server-option
+~~~~~~~~~~~~~~~
+
+If advertised, indicates that any number of server specific options can be
+included in a request.  This is done by sending each option as a
+"server-option=<option>" capability line in the capability-list section of
+a request.
+
+The provided options must not contain a NUL or LF character.

builtin/fetch.c

@@ -62,6 +62,7 @@ static int shown_url = 0;
 static int refmap_alloc, refmap_nr;
 static const char **refmap_array;
 static struct list_objects_filter_options filter_options;
+static struct string_list server_options = STRING_LIST_INIT_DUP;
 
 static int git_fetch_config(const char *k, const char *v, void *cb)
 {
@@ -170,6 +171,7 @@ static struct option builtin_fetch_options[] = {
 		 N_("accept refs that update .git/shallow")),
 	{ OPTION_CALLBACK, 0, "refmap", NULL, N_("refmap"),
 	  N_("specify fetch refmap"), PARSE_OPT_NONEG, parse_refmap_arg },
+	OPT_STRING_LIST('o', "server-option", &server_options, N_("server-specific"), N_("option to transmit")),
 	OPT_SET_INT('4', "ipv4", &family, N_("use IPv4 addresses only"),
 			TRANSPORT_FAMILY_IPV4),
 	OPT_SET_INT('6', "ipv6", &family, N_("use IPv6 addresses only"),
@@ -1417,6 +1419,9 @@ static int fetch_one(struct remote *remote, int argc, const char **argv, int pru
 		}
 	}
 
+	if (server_options.nr)
+		gtransport->server_options = &server_options;
+
 	sigchain_push_common(unlock_pack_on_signal);
 	atexit(unlock_pack);
 	refspec = parse_fetch_refspec(ref_nr, refs);

builtin/ls-remote.c

@@ -47,6 +47,7 @@ int cmd_ls_remote(int argc, const char **argv, const char *prefix)
 	const char **pattern = NULL;
 	struct argv_array ref_prefixes = ARGV_ARRAY_INIT;
 	int i;
+	struct string_list server_options = STRING_LIST_INIT_DUP;
 
 	struct remote *remote;
 	struct transport *transport;
@@ -73,6 +74,7 @@ int cmd_ls_remote(int argc, const char **argv, const char *prefix)
 			      2, PARSE_OPT_NOCOMPLETE),
 		OPT_BOOL(0, "symref", &show_symref_target,
 			 N_("show underlying ref in addition to the object pointed by it")),
+		OPT_STRING_LIST('o', "server-option", &server_options, N_("server-specific"), N_("option to transmit")),
 		OPT_END()
 	};
 
@@ -116,6 +118,8 @@ int cmd_ls_remote(int argc, const char **argv, const char *prefix)
 	transport = transport_get(remote, NULL);
 	if (uploadpack != NULL)
 		transport_set_option(transport, TRANS_OPT_UPLOADPACK, uploadpack);
+	if (server_options.nr)
+		transport->server_options = &server_options;
 
 	ref = transport_get_remote_refs(transport, &ref_prefixes);
 	if (transport_disconnect(transport)) {

connect.c

@@ -408,7 +408,8 @@ out:
 
 struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
 			     struct ref **list, int for_push,
-			     const struct argv_array *ref_prefixes)
+			     const struct argv_array *ref_prefixes,
+			     const struct string_list *server_options)
 {
 	int i;
 	*list = NULL;
@@ -419,6 +420,12 @@ struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
 	if (server_supports_v2("agent", 0))
 		packet_write_fmt(fd_out, "agent=%s", git_user_agent_sanitized());
 
+	if (server_options && server_options->nr &&
+	    server_supports_v2("server-option", 1))
+		for (i = 0; i < server_options->nr; i++)
+			packet_write_fmt(fd_out, "server-option=%s",
+					 server_options->items[i].string);
+
 	packet_delim(fd_out);
 	/* When pushing we don't want to request the peeled tags */
 	if (!for_push)

fetch-pack.c

@@ -1174,6 +1174,13 @@ static int send_fetch_request(int fd_out, const struct fetch_pack_args *args,
 		packet_buf_write(&req_buf, "command=fetch");
 	if (server_supports_v2("agent", 0))
 		packet_buf_write(&req_buf, "agent=%s", git_user_agent_sanitized());
+	if (args->server_options && args->server_options->nr &&
+	    server_supports_v2("server-option", 1)) {
+		int i;
+		for (i = 0; i < args->server_options->nr; i++)
+			packet_write_fmt(fd_out, "server-option=%s",
+					 args->server_options->items[i].string);
+	}
 
 	packet_buf_delim(&req_buf);
 	if (args->use_thin_pack)

fetch-pack.h

@@ -15,6 +15,7 @@ struct fetch_pack_args {
 	const char *deepen_since;
 	const struct string_list *deepen_not;
 	struct list_objects_filter_options filter_options;
+	const struct string_list *server_options;
 	unsigned deepen_relative:1;
 	unsigned quiet:1;
 	unsigned keep_pack:1;

remote.h

@@ -153,6 +153,7 @@ void free_refs(struct ref *ref);
 struct oid_array;
 struct packet_reader;
 struct argv_array;
+struct string_list;
 extern struct ref **get_remote_heads(struct packet_reader *reader,
 				     struct ref **list, unsigned int flags,
 				     struct oid_array *extra_have,
@@ -161,7 +162,8 @@ extern struct ref **get_remote_heads(struct packet_reader *reader,
 /* Used for protocol v2 in order to retrieve refs from a remote */
 extern struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
 				    struct ref **list, int for_push,
-				    const struct argv_array *ref_prefixes);
+				    const struct argv_array *ref_prefixes,
+				    const struct string_list *server_options);
 
 int resolve_remote_symref(struct ref *ref, struct ref *list);
 int ref_newer(const struct object_id *new_oid, const struct object_id *old_oid);

serve.c

@@ -56,6 +56,7 @@ static struct protocol_capability capabilities[] = {
 	{ "agent", agent_advertise, NULL },
 	{ "ls-refs", always_advertise, ls_refs },
 	{ "fetch", upload_pack_advertise, upload_pack_v2 },
+	{ "server-option", always_advertise, NULL },
 };
 
 static void advertise_capabilities(void)

t/t5701-git-serve.sh

@@ -10,6 +10,7 @@ test_expect_success 'test capability advertisement' '
 	agent=git/$(git version | cut -d" " -f3)
 	ls-refs
 	fetch=shallow
+	server-option
 	0000
 	EOF
 
@@ -173,4 +174,24 @@ test_expect_success 'symrefs parameter' '
 	test_cmp actual expect
 '
 
+test_expect_success 'sending server-options' '
+	test-pkt-line pack >in <<-EOF &&
+	command=ls-refs
+	server-option=hello
+	server-option=world
+	0001
+	ref-prefix HEAD
+	0000
+	EOF
+
+	cat >expect <<-EOF &&
+	$(git rev-parse HEAD) HEAD
+	0000
+	EOF
+
+	git serve --stateless-rpc <in >out &&
+	test-pkt-line unpack <out >actual &&
+	test_cmp actual expect
+'
+
 test_done

t/t5702-protocol-v2.sh

@@ -154,6 +154,22 @@ test_expect_success 'ref advertisment is filtered with ls-remote using protocol
 	test_cmp actual expect
 '
 
+test_expect_success 'server-options are sent when using ls-remote' '
+	test_when_finished "rm -f log" &&
+
+	GIT_TRACE_PACKET="$(pwd)/log" git -c protocol.version=2 \
+		ls-remote -o hello -o world "file://$(pwd)/file_parent" master >actual &&
+
+	cat >expect <<-EOF &&
+	$(git -C file_parent rev-parse refs/heads/master)$(printf "\t")refs/heads/master
+	EOF
+
+	test_cmp actual expect &&
+	grep "server-option=hello" log &&
+	grep "server-option=world" log
+'
+
+
 test_expect_success 'clone with file:// using protocol v2' '
 	test_when_finished "rm -f log" &&
 
@@ -201,6 +217,22 @@ test_expect_success 'ref advertisment is filtered during fetch using protocol v2
 	! grep "refs/tags/three" log
 '
 
+test_expect_success 'server-options are sent when fetching' '
+	test_when_finished "rm -f log" &&
+
+	test_commit -C file_parent four &&
+
+	GIT_TRACE_PACKET="$(pwd)/log" git -C file_child -c protocol.version=2 \
+		fetch -o hello -o world origin master &&
+
+	git -C file_child log -1 --format=%s origin/master >actual &&
+	git -C file_parent log -1 --format=%s >expect &&
+	test_cmp expect actual &&
+
+	grep "server-option=hello" log &&
+	grep "server-option=world" log
+'
+
 # Test protocol v2 with 'http://' transport
 #
 . "$TEST_DIRECTORY"/lib-httpd.sh

transport.c

@@ -268,7 +268,7 @@ static struct ref *get_refs_via_connect(struct transport *transport, int for_pus
 	switch (data->version) {
 	case protocol_v2:
 		get_remote_refs(data->fd[1], &reader, &refs, for_push,
-				ref_prefixes);
+				ref_prefixes, transport->server_options);
 		break;
 	case protocol_v1:
 	case protocol_v0:
@@ -316,6 +316,7 @@ static int fetch_refs_via_pack(struct transport *transport,
 	args.no_dependents = data->options.no_dependents;
 	args.filter_options = data->options.filter_options;
 	args.stateless_rpc = transport->stateless_rpc;
+	args.server_options = transport->server_options;
 
 	if (!data->got_remote_heads)
 		refs_tmp = get_refs_via_connect(transport, 0, NULL);

transport.h

@@ -71,6 +71,12 @@ struct transport {
 	 */
 	const struct string_list *push_options;
 
+	/*
+	 * These strings will be passed to the remote side on each command
+	 * request, if both sides support the server-option capability.
+	 */
+	const struct string_list *server_options;
+
 	char *pack_lockfile;
 	signed verbose : 3;
 	/**