.

original commit: 69fc1cca1cab5f4a52a88c9ea043df840ae9e4a0

collects/framework/private/editor.ss

@@ -394,6 +394,7 @@
       (define file<%> 
         (interface (-keymap<%>)
           get-filename/untitled-name
+          get-can-close-parent
           update-frame-filename))
       (define file-mixin
 	(mixin (-keymap<%>) (file<%>)
@@ -467,13 +468,16 @@
                                (get-filename/untitled-name)
                                (string-constant close-anyway)
                                #t
-                               this)
+                               (or (get-top-level-window)
+                                   (get-can-close-parent)))
                           [(continue) #t]
                           [(save) (save-file)]
                           [else #f]))])
               (and user-allowed-or-not-modified
                    (super-can-close?))))
           
+          (define/public (get-can-close-parent) #f)
+          
           (define/override (get-keymaps)
             (cons (keymap:get-file) (super-get-keymaps)))
           (super-new)))