From 9759578f6ce5ee9565a8dbbb3410d47b3a502095 Mon Sep 17 00:00:00 2001
From: "Richard M. Stallman" <rms@gnu.org>
Date: Thu, 4 Aug 1994 23:31:12 +0000
Subject: [PATCH] (frame-delete-all): Copy the whole alist first.

---
 lisp/frame.el | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lisp/frame.el b/lisp/frame.el
index 0688b3098d5..b529afc8981 100644
--- a/lisp/frame.el
+++ b/lisp/frame.el
@@ -336,6 +336,7 @@ These supersede the values given in `default-frame-alist'.")
 ;; Delete from ALIST all elements whose car is KEY.
 ;; Return the modified alist.
 (defun frame-delete-all (key alist)
+  (setq alist (copy-sequence alist))
   (let ((tail alist))
     (while tail
       (if (eq (car (car tail)) key)
-- 
2.39.5