refresh_cache_or_die(refresh_flags);
 
-               if (write_locked_index(&the_index, &index_lock, CLOSE_LOCK))
+               if (write_locked_index(&the_index, &index_lock, 0))
                        die(_("unable to create temporary index"));
 
                old_index_env = getenv(INDEX_ENVIRONMENT);
                if (update_main_cache_tree(WRITE_TREE_SILENT) == 0) {
                        if (reopen_lock_file(&index_lock) < 0)
                                die(_("unable to write index file"));
-                       if (write_locked_index(&the_index, &index_lock, CLOSE_LOCK))
+                       if (write_locked_index(&the_index, &index_lock, 0))
                                die(_("unable to update temporary index"));
                } else
                        warning(_("Failed to update main cache tree"));
                add_files_to_cache(also ? prefix : NULL, &pathspec, 0);
                refresh_cache_or_die(refresh_flags);
                update_main_cache_tree(WRITE_TREE_SILENT);
-               if (write_locked_index(&the_index, &index_lock, CLOSE_LOCK))
+               if (write_locked_index(&the_index, &index_lock, 0))
                        die(_("unable to write new_index file"));
                commit_style = COMMIT_NORMAL;
                ret = get_lock_file_path(&index_lock);
        add_remove_files(&partial);
        refresh_cache(REFRESH_QUIET);
        update_main_cache_tree(WRITE_TREE_SILENT);
-       if (write_locked_index(&the_index, &index_lock, CLOSE_LOCK))
+       if (write_locked_index(&the_index, &index_lock, 0))
                die(_("unable to write new_index file"));
 
        hold_lock_file_for_update(&false_lock,
        add_remove_files(&partial);
        refresh_cache(REFRESH_QUIET);
 
-       if (write_locked_index(&the_index, &false_lock, CLOSE_LOCK))
+       if (write_locked_index(&the_index, &false_lock, 0))
                die(_("unable to write temporary index file"));
 
        discard_cache();
        diff_setup_done(&rev.diffopt);
 
        head = resolve_ref_unsafe("HEAD", 0, NULL, NULL);
+       if (!head)
+               die_errno(_("unable to resolve HEAD after creating commit"));
        if (!strcmp(head, "HEAD"))
                head = _("detached HEAD");
        else