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

1 files changed, 9 insertions, 1 deletions

diff --git a/lisp/menu-bar.el b/lisp/menu-bar.el
index 6415eac958d..f6150a9a31b 100644
--- 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