Use project-root instead of cdr; closes #752

Author: greghendershott

racket-util.el

@@ -1,6 +1,6 @@
 ;;; racket-util.el -*- lexical-binding: t -*-
 
-;; Copyright (c) 2013-2022 by Greg Hendershott.
+;; Copyright (c) 2013-2022, 2025 by Greg Hendershott.
 ;; Portions Copyright (C) 1985-1986, 1999-2013 Free Software Foundation, Inc.
 
 ;; Author: Greg Hendershott
@@ -117,8 +117,11 @@ The \"project\" is determined by trying, in order:
              (projectile-project-root dir))
         (and (fboundp 'vc-root-dir)
              (vc-root-dir))
-        (and (fboundp 'project-current)
-             (cdr (project-current nil dir)))
+        (and (require 'project nil 'noerror)
+             (fboundp 'project-current)
+             (fboundp 'project-root)
+             (when-let (pr (project-current nil dir))
+               (project-root pr)))
         dir)))
 
 (defun racket--edit-mode-p ()