> ;; (BEGIN . END)
> (and (>= (car undo-elt) start)
> (<= (cdr undo-elt) end))
> ^^
>
> ;; (TEXT . POSITION)
> (and (>= (abs (cdr undo-elt)) start)
> (< (abs (cdr undo-elt)) end))
> ^
Using 'git log -L' on these two code fragments, I found the (BEGIN .
END) case changed in this commit to "Fix one-off error at END".
commit 9debee7a5e6ebc0c32141619248e7390f1476946
Author: Richard M. Stallman <
rms@gnu.org>
Date: Mon Sep 9 00:27:30 2002 +0000
(undo-elt-in-region): Fix one-off error at END.
(forward-visible-line): Handle invisibility by ignoring
invisible newlines. Also include entire invisible lines beyond
the stopping point.
diff --git a/lisp/simple.el b/lisp/simple.el
index bfef653..d9ae114 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -1089,7 +1089,7 @@ we stop and ignore all further elements."
If it crosses the edge, we return nil."
(cond ((integerp undo-elt)
(and (>= undo-elt start)
- (< undo-elt end)))
+ (<= undo-elt end)))
((eq undo-elt nil)
t)
((atom undo-elt)
@@ -1109,16 +1109,16 @@ If it crosses the edge, we return nil."
(cons alist-elt undo-adjusted-markers)))
(and (cdr alist-elt)
(>= (cdr alist-elt) start)
- (< (cdr alist-elt) end))))
+ (<= (cdr alist-elt) end))))
((null (car undo-elt))
;; (nil PROPERTY VALUE BEG . END)
(let ((tail (nthcdr 3 undo-elt)))
(and (>= (car tail) start)
- (< (cdr tail) end))))
+ (<= (cdr tail) end))))
((integerp (car undo-elt))
;; (BEGIN . END)
(and (>= (car undo-elt) start)
- (< (cdr undo-elt) end)))))
+ (<= (cdr undo-elt) end)))))
(defun undo-elt-crosses-region (undo-elt start end)
"Test whether UNDO-ELT crosses one edge of that region START ... END.
This didn't change the (TEXT . POSITION) case, which hasn't changed
since 1998 when it was first introduced. Maybe it was forgotten in the
above 2002 change?
Anyway, I made this change locally:
diff --git a/lisp/simple.el b/lisp/simple.el
index b90382d..01d4f19 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -2434,7 +2434,7 @@ If it crosses the edge, we return nil."
((stringp (car undo-elt))
;; (TEXT . POSITION)
(and (>= (abs (cdr undo-elt)) start)
- (< (abs (cdr undo-elt)) end)))
+ (<= (abs (cdr undo-elt)) end)))
((and (consp undo-elt) (markerp (car undo-elt)))
;; This is a marker-adjustment element (MARKER . ADJUSTMENT).
;; See if MARKER is inside the region.
and I didn't witness the incorrect behavior from undo in region.
Another justification for this change, in addition to fixing the
buffer corruption my recipe demonstrates, is that without it, a
deletion at the EOB is inaccessible via undo in region.