Merge branch 'jk/receive-pack-deadlocks-with-early-failure'

When receive-pack detects error in the pack header it received in
order to decide which of unpack-objects or index-pack to run, it
returned without closing the error stream, which led to a hang
sideband thread.

* jk/receive-pack-deadlocks-with-early-failure:
receive-pack: close sideband fd on early pack errors

diff --combined builtin/receive-pack.c
index ccebd74f166f5d02e8e6a0bb6033d741f8580f7b,ce42c0a5263e54596003d2c9f4d39e0435326f78..e3eb5fc0588a79b2b6c29bccdaf71ba49dc14c1f
--- 1/builtin/receive-pack.c
--- 2/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@@ -59,11 -59,6 +59,11 @@@ static enum deny_action parse_deny_acti
  
  static int receive_pack_config(const char *var, const char *value, void *cb)
  {
 +      int status = parse_hide_refs_config(var, value, "receive");
 +
 +      if (status)
 +              return status;
 +
        if (strcmp(var, "receive.denydeletes") == 0) {
                deny_deletes = git_config_bool(var, value);
                return 0;
@@@ -124,9 -119,6 +124,9 @@@
  
  static void show_ref(const char *path, const unsigned char *sha1)
  {
 +      if (ref_is_hidden(path))
 +              return;
 +
        if (sent_capabilities)
                packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
        else
@@@ -190,6 -182,9 +190,6 @@@ struct command 
        char ref_name[FLEX_ARRAY]; /* more */
  };
  
 -static const char pre_receive_hook[] = "hooks/pre-receive";
 -static const char post_receive_hook[] = "hooks/post-receive";
 -
  static void rp_error(const char *err, ...) __attribute__((format (printf, 1, 2)));
  static void rp_warning(const char *err, ...) __attribute__((format (printf, 1, 2)));
  
@@@ -247,10 -242,10 +247,10 @@@ static int run_and_feed_hook(const cha
        const char *argv[2];
        int code;
  
 -      if (access(hook_name, X_OK) < 0)
 +      argv[0] = find_hook(hook_name);
 +      if (!argv[0])
                return 0;
  
 -      argv[0] = hook_name;
        argv[1] = NULL;
  
        memset(&proc, 0, sizeof(proc));
@@@ -336,14 -331,15 +336,14 @@@ static int run_receive_hook(struct comm
  
  static int run_update_hook(struct command *cmd)
  {
 -      static const char update_hook[] = "hooks/update";
        const char *argv[5];
        struct child_process proc;
        int code;
  
 -      if (access(update_hook, X_OK) < 0)
 +      argv[0] = find_hook("update");
 +      if (!argv[0])
                return 0;
  
 -      argv[0] = update_hook;
        argv[1] = cmd->ref_name;
        argv[2] = sha1_to_hex(cmd->old_sha1);
        argv[3] = sha1_to_hex(cmd->new_sha1);
@@@ -536,25 -532,24 +536,25 @@@ static const char *update(struct comman
        }
  }
  
 -static char update_post_hook[] = "hooks/post-update";
 -
  static void run_update_post_hook(struct command *commands)
  {
        struct command *cmd;
        int argc;
        const char **argv;
        struct child_process proc;
 +      char *hook;
  
 +      hook = find_hook("post-update");
        for (argc = 0, cmd = commands; cmd; cmd = cmd->next) {
                if (cmd->error_string || cmd->did_not_exist)
                        continue;
                argc++;
        }
 -      if (!argc || access(update_post_hook, X_OK) < 0)
 +      if (!argc || !hook)
                return;
 +
        argv = xmalloc(sizeof(*argv) * (2 + argc));
 -      argv[0] = update_post_hook;
 +      argv[0] = hook;
  
        for (argc = 1, cmd = commands; cmd; cmd = cmd->next) {
                char *p;
@@@ -693,20 -688,6 +693,20 @@@ static int iterate_receive_command_list
        return -1; /* end of list */
  }
  
 +static void reject_updates_to_hidden(struct command *commands)
 +{
 +      struct command *cmd;
 +
 +      for (cmd = commands; cmd; cmd = cmd->next) {
 +              if (cmd->error_string || !ref_is_hidden(cmd->ref_name))
 +                      continue;
 +              if (is_null_sha1(cmd->new_sha1))
 +                      cmd->error_string = "deny deleting a hidden ref";
 +              else
 +                      cmd->error_string = "deny updating a hidden ref";
 +      }
 +}
 +
  static void execute_commands(struct command *commands, const char *unpacker_error)
  {
        struct command *cmd;
@@@ -723,9 -704,7 +723,9 @@@
                                       0, &cmd))
                set_connectivity_errors(commands);
  
 -      if (run_receive_hook(commands, pre_receive_hook, 0)) {
 +      reject_updates_to_hidden(commands);
 +
 +      if (run_receive_hook(commands, "pre-receive", 0)) {
                for (cmd = commands; cmd; cmd = cmd->next) {
                        if (!cmd->error_string)
                                cmd->error_string = "pre-receive hook declined";
@@@ -754,15 -733,17 +754,15 @@@ static struct command *read_head_info(v
        struct command *commands = NULL;
        struct command **p = &commands;
        for (;;) {
 -              static char line[1000];
 +              char *line;
                unsigned char old_sha1[20], new_sha1[20];
                struct command *cmd;
                char *refname;
                int len, reflen;
  
 -              len = packet_read_line(0, line, sizeof(line));
 -              if (!len)
 +              line = packet_read_line(0, &len);
 +              if (!line)
                        break;
 -              if (line[len-1] == '\n')
 -                      line[--len] = 0;
                if (len < 83 ||
                    line[40] != ' ' ||
                    line[81] != ' ' ||
@@@ -826,8 -807,11 +826,11 @@@ static const char *unpack(int err_fd
                            : 0);
  
        hdr_err = parse_pack_header(&hdr);
-       if (hdr_err)
+       if (hdr_err) {
+               if (err_fd > 0)
+                       close(err_fd);
                return hdr_err;
+       }
        snprintf(hdr_arg, sizeof(hdr_arg),
                        "--pack_header=%"PRIu32",%"PRIu32,
                        ntohl(hdr.hdr_version), ntohl(hdr.hdr_entries));
@@@ -930,7 -914,7 +933,7 @@@ static void report(struct command *comm
        if (use_sideband)
                send_sideband(1, 1, buf.buf, buf.len, use_sideband);
        else
 -              safe_write(1, buf.buf, buf.len);
 +              write_or_die(1, buf.buf, buf.len);
        strbuf_release(&buf);
  }
  
@@@ -1013,7 -997,7 +1016,7 @@@ int cmd_receive_pack(int argc, const ch
                        unlink_or_warn(pack_lockfile);
                if (report_status)
                        report(commands, unpack_status);
 -              run_receive_hook(commands, post_receive_hook, 1);
 +              run_receive_hook(commands, "post-receive", 1);
                run_update_post_hook(commands);
                if (auto_gc) {
                        const char *argv_gc_auto[] = {