(undo-auto--boundary-ensure-timer))
;; End auto-boundary section
+(defun undo-amalgamate-change-group (handle)
+ "Amalgamate changes in change-group since HANDLE.
+Remove all undo boundaries between the state of HANDLE and now.
+HANDLE is as returned by `prepare-change-group'."
+ (dolist (elt handle)
+ (with-current-buffer (car elt)
+ (setq elt (cdr elt))
+ (when (consp buffer-undo-list)
+ (let ((old-car (car-safe elt))
+ (old-cdr (cdr-safe elt)))
+ (unwind-protect
+ (progn
+ ;; Temporarily truncate the undo log at ELT.
+ (when (consp elt)
+ (setcar elt t) (setcdr elt nil))
+ (when
+ (or (null elt) ;The undo-log was empty.
+ ;; `elt' is still in the log: normal case.
+ (eq elt (last buffer-undo-list))
+ ;; `elt' is not in the log any more, but that's because
+ ;; the log is "all new", so we should remove all
+ ;; boundaries from it.
+ (not (eq (last buffer-undo-list) (last old-cdr))))
+ (cl-callf (lambda (x) (delq nil x))
+ (if (car buffer-undo-list)
+ buffer-undo-list
+ ;; Preserve the undo-boundaries at either ends of the
+ ;; change-groups.
+ (cdr buffer-undo-list)))))
+ ;; Reset the modified cons cell ELT to its original content.
+ (when (consp elt)
+ (setcar elt old-car)
+ (setcdr elt old-cdr))))))))
+
+
(defcustom undo-ask-before-discard nil
"If non-nil ask about discarding undo info for the current command.
Normally, Emacs discards the undo info for the current command if