* lisp/winner.el (winner-change-fun): Cull dead frames.
This prevents a potentially massive memory leak. See:
http://lists.gnu.org/archive/html/emacs-devel/2015-09/msg00619.html
;; Called whenever the window configuration changes
;; (a `window-configuration-change-hook').
(defun winner-change-fun ()
+
+ ;; Cull dead frames.
+ (setq winner-modified-list
+ (cl-remove-if-not 'frame-live-p winner-modified-list))
+
(unless (or (memq (selected-frame) winner-modified-list)
(/= 0 (minibuffer-depth)))
(push (selected-frame) winner-modified-list)))