fetch-pack: advertise session ID in capabilities

When the server sent a session-id capability and transfer.advertiseSID
is true, advertise fetch-pack's own session ID back to the server.

Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/fetch-pack.c b/fetch-pack.c
index b10c4323155b77f2ef271564cef862147a880596..23179b8dd0250a700dec847d0c2916d7a8660917 100644 (file)
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -35,6 +35,7 @@ static int fetch_fsck_objects = -1;
 static int transfer_fsck_objects = -1;
 static int agent_supported;
 static int server_supports_filtering;
+static int advertise_sid;
 static struct shallow_lock shallow_lock;
 static const char *alternate_shallow_file;
 static struct strbuf fsck_msg_types = STRBUF_INIT;
@@ -326,6 +327,8 @@ static int find_common(struct fetch_negotiator *negotiator,
                        if (deepen_not_ok)      strbuf_addstr(&c, " deepen-not");
                        if (agent_supported)    strbuf_addf(&c, " agent=%s",
                                                            git_user_agent_sanitized());
+                       if (advertise_sid)
+                               strbuf_addf(&c, " session-id=%s", trace2_session_id());
                        if (args->filter_options.choice)
                                strbuf_addstr(&c, " filter");
                        packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
@@ -979,6 +982,9 @@ static struct ref *do_fetch_pack(struct fetch_pack_args *args,
                                      agent_len, agent_feature);
        }
 
+       if (!server_supports("session-id"))
+               advertise_sid = 0;
+
        if (server_supports("shallow"))
                print_verbose(args, _("Server supports %s"), "shallow");
        else if (args->depth > 0 || is_repository_shallow(r))
@@ -1191,6 +1197,8 @@ static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
                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 (advertise_sid && server_supports_v2("session-id", 0))
+               packet_buf_write(&req_buf, "session-id=%s", trace2_session_id());
        if (args->server_options && args->server_options->nr &&
            server_supports_v2("server-option", 1)) {
                int i;
@@ -1711,6 +1719,7 @@ static void fetch_pack_config(void)
        git_config_get_bool("repack.usedeltabaseoffset", &prefer_ofs_delta);
        git_config_get_bool("fetch.fsckobjects", &fetch_fsck_objects);
        git_config_get_bool("transfer.fsckobjects", &transfer_fsck_objects);
+       git_config_get_bool("transfer.advertisesid", &advertise_sid);
        if (!uri_protocols.nr) {
                char *str;