send-pack/receive-pack: allow errors to be reported back to pusher.

This updates the protocol between git-send-pack/git-receive-pack
in a backward compatible way to allow failures at the receiving
end to be propagated back to the sender.  Most notably, versions
of git-push before this could not notice if the update hook on
the receiving end refused to update the ref for its own policy
reasons.

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/connect.c b/connect.c
index 6b6d613..d6f4e4c 100644 (file)
--- a/connect.c
+++ b/connect.c
@@ -34,10 +34,6 @@ struct ref **get_remote_heads(int in, struct ref **list,
                        die("protocol error: expected sha/ref, got '%s'", buffer);
                name = buffer + 41;
 
-               if (ignore_funny && 45 < len && !memcmp(name, "refs/", 5) &&
-                   check_ref_format(name + 5))
-                       continue;
-
                name_len = strlen(name);
                if (len != name_len + 41) {
                        if (server_capabilities)
@@ -45,6 +41,10 @@ struct ref **get_remote_heads(int in, struct ref **list,
                        server_capabilities = strdup(name + name_len + 1);
                }
 
+               if (ignore_funny && 45 < len && !memcmp(name, "refs/", 5) &&
+                   check_ref_format(name + 5))
+                       continue;
+
                if (nr_match && !path_match(name, nr_match, match))
                        continue;
                ref = xcalloc(1, sizeof(*ref) + len - 40);

diff --git a/receive-pack.c b/receive-pack.c
index 92878ec..e79de91 100644 (file)
--- a/receive-pack.c
+++ b/receive-pack.c
@@ -8,20 +8,33 @@ static const char receive_pack_usage[] = "git-receive-pack <git-dir>";
 
 static const char unpacker[] = "git-unpack-objects";
 
+static int report_status = 0;
+
+static char capabilities[] = "report-status";
+static int capabilities_sent = 0;
+
 static int show_ref(const char *path, const unsigned char *sha1)
 {
-       packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
+       if (capabilities_sent)
+               packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
+       else
+               packet_write(1, "%s %s%c%s\n",
+                            sha1_to_hex(sha1), path, 0, capabilities);
+       capabilities_sent = 1;
        return 0;
 }
 
 static void write_head_info(void)
 {
        for_each_ref(show_ref);
+       if (!capabilities_sent)
+               show_ref("capabilities^{}", null_sha1);
+
 }
 
 struct command {
        struct command *next;
-       unsigned char updated;
+       const char *error_string;
        unsigned char old_sha1[20];
        unsigned char new_sha1[20];
        char ref_name[0];
@@ -71,33 +84,37 @@ static int run_update_hook(const char *refname,
        case 0:
                return 0;
        case -ERR_RUN_COMMAND_FORK:
-               die("hook fork failed");
+               return error("hook fork failed");
        case -ERR_RUN_COMMAND_EXEC:
-               die("hook execute failed");
+               return error("hook execute failed");
        case -ERR_RUN_COMMAND_WAITPID:
-               die("waitpid failed");
+               return error("waitpid failed");
        case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
-               die("waitpid is confused");
+               return error("waitpid is confused");
        case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
-               fprintf(stderr, "%s died of signal\n", update_hook);
-               return -1;
+               return error("%s died of signal\n", update_hook);
        case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
-               die("%s died strangely", update_hook);
+               return error("%s died strangely", update_hook);
        default:
                error("%s exited with error code %d", update_hook, -code);
                return -code;
        }
 }
 
-static int update(const char *name,
-                 unsigned char *old_sha1, unsigned char *new_sha1)
+static int update(struct command *cmd)
 {
+       const char *name = cmd->ref_name;
+       unsigned char *old_sha1 = cmd->old_sha1;
+       unsigned char *new_sha1 = cmd->new_sha1;
        char new_hex[60], *old_hex, *lock_name;
        int newfd, namelen, written;
 
-       if (!strncmp(name, "refs/", 5) && check_ref_format(name + 5))
+       cmd->error_string = NULL;
+       if (!strncmp(name, "refs/", 5) && check_ref_format(name + 5)) {
+               cmd->error_string = "funny refname";
                return error("refusing to create funny ref '%s' locally",
                             name);
+       }
 
        namelen = strlen(name);
        lock_name = xmalloc(namelen + 10);
@@ -106,16 +123,19 @@ static int update(const char *name,
 
        strcpy(new_hex, sha1_to_hex(new_sha1));
        old_hex = sha1_to_hex(old_sha1);
-       if (!has_sha1_file(new_sha1))
+       if (!has_sha1_file(new_sha1)) {
+               cmd->error_string = "bad pack";
                return error("unpack should have generated %s, "
                             "but I can't find it!", new_hex);
-
+       }
        safe_create_leading_directories(lock_name);
 
        newfd = open(lock_name, O_CREAT | O_EXCL | O_WRONLY, 0666);
-       if (newfd < 0)
+       if (newfd < 0) {
+               cmd->error_string = "can't lock";
                return error("unable to create %s (%s)",
                             lock_name, strerror(errno));
+       }
 
        /* Write the ref with an ending '\n' */
        new_hex[40] = '\n';
@@ -127,18 +147,22 @@ static int update(const char *name,
        close(newfd);
        if (written != 41) {
                unlink(lock_name);
+               cmd->error_string = "can't write";
                return error("unable to write %s", lock_name);
        }
        if (verify_old_ref(name, old_hex) < 0) {
                unlink(lock_name);
+               cmd->error_string = "raced";
                return error("%s changed during push", name);
        }
        if (run_update_hook(name, old_hex, new_hex)) {
                unlink(lock_name);
+               cmd->error_string = "hook declined";
                return error("hook declined to update %s\n", name);
        }
        else if (rename(lock_name, name) < 0) {
                unlink(lock_name);
+               cmd->error_string = "can't rename";
                return error("unable to replace %s", name);
        }
        else {
@@ -158,7 +182,7 @@ static void run_update_post_hook(struct command *cmd)
        if (access(update_post_hook, X_OK) < 0)
                return;
        for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
-               if (!cmd_p->updated)
+               if (cmd_p->error_string)
                        continue;
                argc++;
        }
@@ -166,7 +190,7 @@ static void run_update_post_hook(struct command *cmd)
        argv[0] = update_post_hook;
 
        for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
-               if (!cmd_p->updated)
+               if (cmd_p->error_string)
                        continue;
                argv[argc] = xmalloc(strlen(cmd_p->ref_name) + 1);
                strcpy(argv[argc], cmd_p->ref_name);
@@ -185,8 +209,7 @@ static void execute_commands(void)
        struct command *cmd = commands;
 
        while (cmd) {
-               cmd->updated = !update(cmd->ref_name,
-                                      cmd->old_sha1, cmd->new_sha1);
+               update(cmd);
                cmd = cmd->next;
        }
        run_update_post_hook(commands);
@@ -199,7 +222,8 @@ static void read_head_info(void)
                static char line[1000];
                unsigned char old_sha1[20], new_sha1[20];
                struct command *cmd;
-               int len;
+               char *refname;
+               int len, reflen;
 
                len = packet_read_line(0, line, sizeof(line));
                if (!len)
@@ -211,38 +235,66 @@ static void read_head_info(void)
                    line[81] != ' ' ||
                    get_sha1_hex(line, old_sha1) ||
                    get_sha1_hex(line + 41, new_sha1))
-                       die("protocol error: expected old/new/ref, got '%s'", line);
+                       die("protocol error: expected old/new/ref, got '%s'",
+                           line);
+
+               refname = line + 82;
+               reflen = strlen(refname);
+               if (reflen + 82 < len) {
+                       if (strstr(refname + reflen + 1, "report-status"))
+                               report_status = 1;
+               }
                cmd = xmalloc(sizeof(struct command) + len - 80);
                memcpy(cmd->old_sha1, old_sha1, 20);
                memcpy(cmd->new_sha1, new_sha1, 20);
                memcpy(cmd->ref_name, line + 82, len - 81);
+               cmd->error_string = "n/a (unpacker error)";
                cmd->next = NULL;
                *p = cmd;
                p = &cmd->next;
        }
 }
 
-static void unpack(void)
+static const char *unpack(int *error_code)
 {
        int code = run_command(unpacker, NULL);
+
+       *error_code = 0;
        switch (code) {
        case 0:
-               return;
+               return NULL;
        case -ERR_RUN_COMMAND_FORK:
-               die("unpack fork failed");
+               return "unpack fork failed";
        case -ERR_RUN_COMMAND_EXEC:
-               die("unpack execute failed");
+               return "unpack execute failed";
        case -ERR_RUN_COMMAND_WAITPID:
-               die("waitpid failed");
+               return "waitpid failed";
        case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
-               die("waitpid is confused");
+               return "waitpid is confused";
        case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
-               die("%s died of signal", unpacker);
+               return "unpacker died of signal";
        case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
-               die("%s died strangely", unpacker);
+               return "unpacker died strangely";
        default:
-               die("%s exited with error code %d", unpacker, -code);
+               *error_code = -code;
+               return "unpacker exited with error code";
+       }
+}
+
+static void report(const char *unpack_status)
+{
+       struct command *cmd;
+       packet_write(1, "unpack %s\n",
+                    unpack_status ? unpack_status : "ok");
+       for (cmd = commands; cmd; cmd = cmd->next) {
+               if (!cmd->error_string)
+                       packet_write(1, "ok %s\n",
+                                    cmd->ref_name);
+               else
+                       packet_write(1, "ng %s %s\n",
+                                    cmd->ref_name, cmd->error_string);
        }
+       packet_flush(1);
 }
 
 int main(int argc, char **argv)
@@ -275,8 +327,12 @@ int main(int argc, char **argv)
 
        read_head_info();
        if (commands) {
-               unpack();
-               execute_commands();
+               int code;
+               const char *unpack_status = unpack(&code);
+               if (!unpack_status)
+                       execute_commands();
+               if (report_status)
+                       report(unpack_status);
        }
        return 0;
 }

diff --git a/send-pack.c b/send-pack.c
index 0d41f9a..cd36193 100644 (file)
--- a/send-pack.c
+++ b/send-pack.c
@@ -176,16 +176,53 @@ static void get_local_heads(void)
        for_each_ref(one_local_ref);
 }
 
+static int receive_status(int in)
+{
+       char line[1000];
+       int ret = 0;
+       int len = packet_read_line(in, line, sizeof(line));
+       if (len < 10 || memcmp(line, "unpack ", 7)) {
+               fprintf(stderr, "did not receive status back\n");
+               return -1;
+       }
+       if (memcmp(line, "unpack ok\n", 10)) {
+               fputs(line, stderr);
+               ret = -1;
+       }
+       while (1) {
+               len = packet_read_line(in, line, sizeof(line));
+               if (!len)
+                       break;
+               if (len < 3 ||
+                   (memcmp(line, "ok", 2) && memcmp(line, "ng", 2))) {
+                       fprintf(stderr, "protocol error: %s\n", line);
+                       ret = -1;
+                       break;
+               }
+               if (!memcmp(line, "ok", 2))
+                       continue;
+               fputs(line, stderr);
+               ret = -1;
+       }
+       return ret;
+}
+
 static int send_pack(int in, int out, int nr_refspec, char **refspec)
 {
        struct ref *ref;
        int new_refs;
        int ret = 0;
+       int ask_for_status_report = 0;
+       int expect_status_report = 0;
 
        /* No funny business with the matcher */
        remote_tail = get_remote_heads(in, &remote_refs, 0, NULL, 1);
        get_local_heads();
 
+       /* Does the other end support the reporting? */
+       if (server_supports("report-status"))
+               ask_for_status_report = 1;
+
        /* match them up */
        if (!remote_tail)
                remote_tail = &remote_refs;
@@ -260,7 +297,17 @@ static int send_pack(int in, int out, int nr_refspec, char **refspec)
                new_refs++;
                strcpy(old_hex, sha1_to_hex(ref->old_sha1));
                new_hex = sha1_to_hex(ref->new_sha1);
-               packet_write(out, "%s %s %s", old_hex, new_hex, ref->name);
+
+               if (ask_for_status_report) {
+                       packet_write(out, "%s %s %s%c%s",
+                                    old_hex, new_hex, ref->name, 0,
+                                    "report-status");
+                       ask_for_status_report = 0;
+                       expect_status_report = 1;
+               }
+               else
+                       packet_write(out, "%s %s %s",
+                                    old_hex, new_hex, ref->name);
                fprintf(stderr, "updating '%s'", ref->name);
                if (strcmp(ref->name, ref->peer_ref->name))
                        fprintf(stderr, " using '%s'", ref->peer_ref->name);
@@ -270,9 +317,15 @@ static int send_pack(int in, int out, int nr_refspec, char **refspec)
        packet_flush(out);
        if (new_refs)
                pack_objects(out, remote_refs);
-       else if (ret == 0)
-               fprintf(stderr, "Everything up-to-date\n");
        close(out);
+
+       if (expect_status_report) {
+               if (receive_status(in))
+                       ret = -4;
+       }
+
+       if (!new_refs && ret == 0)
+               fprintf(stderr, "Everything up-to-date\n");
        return ret;
 }