git_config(git_default_config, NULL);
        is_bare_repository_cfg = init_is_bare_repository;
+
+       /* reading existing config may have overwrote it */
        if (init_shared_repository != -1)
                shared_repository = init_shared_repository;
 
                 * and compatibility values for PERM_GROUP and
                 * PERM_EVERYBODY.
                 */
-               if (shared_repository == PERM_GROUP)
+               if (shared_repository < 0)
+                       /* force to the mode value */
+                       sprintf(buf, "0%o", -shared_repository);
+               else if (shared_repository == PERM_GROUP)
                        sprintf(buf, "%d", OLD_PERM_GROUP);
                else if (shared_repository == PERM_EVERYBODY)
                        sprintf(buf, "%d", OLD_PERM_EVERYBODY);
                else
-                       sprintf(buf, "0%o", shared_repository);
+                       die("oops");
                git_config_set("core.sharedrepository", buf);
                git_config_set("receive.denyNonFastforwards", "true");
        }
                        usage(init_db_usage);
        }
 
+       if (init_shared_repository != -1)
+               shared_repository = init_shared_repository;
+
        /*
         * GIT_WORK_TREE makes sense only in conjunction with GIT_DIR
         * without --bare.  Catch the error early.