(defalias 'advertised-undo 'undo)
(defconst undo-equiv-table (make-hash-table :test 'eq :weakness t)
- "Table mapping redo records to the corresponding undo one.")
+ "Table mapping redo records to the corresponding undo one.
+A redo record for undo-in-region maps to t.
+A redo record for ordinary undo maps to the following (earlier) undo.")
(defvar undo-in-region nil
"Non-nil if `pending-undo-list' is not just a tail of `buffer-undo-list'.")
(message (if undo-in-region
(if equiv "Redo in region!" "Undo in region!")
(if equiv "Redo!" "Undo!"))))
- (when (and equiv undo-no-redo)
+ (when (and (listp equiv) undo-no-redo)
;; The equiv entry might point to another redo record if we have done
;; undo-redo-undo-redo-... so skip to the very last equiv.
(while (let ((next (gethash equiv undo-equiv-table)))
(prefix-numeric-value arg)
1))
;; Record the fact that the just-generated undo records come from an
- ;; undo operation, so we can skip them later on.
+ ;; undo operation--that is, they are redo records.
+ ;; In the ordinary case (not within a region), map the redo
+ ;; record to the following undos.
;; I don't know how to do that in the undo-in-region case.
- (unless undo-in-region
- (puthash buffer-undo-list pending-undo-list undo-equiv-table))
+ (puthash buffer-undo-list
+ (if undo-in-region t pending-undo-list)
+ undo-equiv-table)
;; Don't specify a position in the undo record for the undo command.
;; Instead, undoing this should move point to where the change is.
(let ((tail buffer-undo-list)