(delete-frame): Permit it, if > 1 frame is vis or iconic.

diff --git a/lisp/menu-bar.el b/lisp/menu-bar.el
index 6415eac958d77680be8c7fedb3c761847acd01b7..f6150a9a31b283f92657063e9623f785e19a685d 100644 (file)
--- a/lisp/menu-bar.el
+++ b/lisp/menu-bar.el
@@ -107,7 +107,15 @@
      '(or revert-buffer-function revert-buffer-insert-file-contents-function
          (and (buffer-file-name)
               (not (verify-visited-file-modtime (current-buffer))))))
-(put 'delete-frame 'menu-enable '(cdr (visible-frame-list)))
+;; Permit deleting frame if it would leave a visible or iconified frame.
+(put 'delete-frame 'menu-enable
+     '(let ((frames (frame-list))
+           (count 0))
+       (while frames
+         (if (cdr (assq 'visibility (frame-parameters (car frames))))
+             (setq count (1+ count)))
+         (setq frames (cdr frames)))
+       (> count 1)))
 (put 'kill-this-buffer 'menu-enable '(kill-this-buffer-enabled-p))
 
 (put 'advertised-undo 'menu-enable