(eval-defun): For defcustom, always set the value.

1 files changed, 8 insertions, 3 deletions

diff --git a/lisp/emacs-lisp/lisp-mode.el b/lisp/emacs-lisp/lisp-mode.el
index ebdee0673ee..be328b30329 100644
--- a/lisp/emacs-lisp/lisp-mode.el
+++ b/lisp/emacs-lisp/lisp-mode.el
@@ -329,9 +329,14 @@ With argument, insert value in current buffer after the defun."
                 (end-of-defun)
                 (beginning-of-defun)
                 (read (current-buffer)))))
-    (if (and (eq (car form) 'defvar)
-             (cdr-safe (cdr-safe form)))
-        (setq form (cons 'defconst (cdr form))))
+    (cond ((and (eq (car form) 'defvar)
+                (cdr-safe (cdr-safe form)))
+           ;; Force variable to be bound.
+           (setq form (cons 'defconst (cdr form))))
+          ((and (eq (car form) 'defcustom)
+                (default-boundp (nth 1 form)))
+           ;; Force variable to be bound.
+           (set-default (nth 1 form) (eval (nth 2 form)))))
     (prin1 (eval form))))
 
 (defun lisp-comment-indent ()