(cancel-change-group): Widen buffer temporarily when

undoing changes.  (Bug#810)

2 files changed, 29 insertions, 20 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 1bb4e7721cf..46404ef3c09 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2008-09-07  Martin Rudalics  <rudalics@gmx.at>
+
+        * subr.el (cancel-change-group): Widen buffer temporarily when
+        undoing changes.  (Bug#810)
+
 2008-09-07  Nick Roberts  <nickrob@snap.net.nz>
 
         * progmodes/gud.el (gud-stop-subjob): Using jdb, suspend threads
diff --git a/lisp/subr.el b/lisp/subr.el
index b7b6b2c38de..2aa802cd03e 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -1993,26 +1993,30 @@ This finishes the change group by reverting all of its changes."
   (dolist (elt handle)
     (with-current-buffer (car elt)
       (setq elt (cdr elt))
-      (let ((old-car
-             (if (consp elt) (car elt)))
-            (old-cdr
-             (if (consp elt) (cdr elt))))
-        ;; Temporarily truncate the undo log at ELT.
-        (when (consp elt)
-          (setcar elt nil) (setcdr elt nil))
-        (unless (eq last-command 'undo) (undo-start))
-        ;; Make sure there's no confusion.
-        (when (and (consp elt) (not (eq elt (last pending-undo-list))))
-          (error "Undoing to some unrelated state"))
-        ;; Undo it all.
-        (save-excursion
-          (while (listp pending-undo-list) (undo-more 1)))
-        ;; Reset the modified cons cell ELT to its original content.
-        (when (consp elt)
-          (setcar elt old-car)
-          (setcdr elt old-cdr))
-        ;; Revert the undo info to what it was when we grabbed the state.
-        (setq buffer-undo-list elt)))))
+      (save-restriction
+        ;; Widen buffer temporarily so if the buffer was narrowed within
+        ;; the body of `atomic-change-group' all changes can be undone.
+        (widen)
+        (let ((old-car
+               (if (consp elt) (car elt)))
+              (old-cdr
+               (if (consp elt) (cdr elt))))
+          ;; Temporarily truncate the undo log at ELT.
+          (when (consp elt)
+            (setcar elt nil) (setcdr elt nil))
+          (unless (eq last-command 'undo) (undo-start))
+          ;; Make sure there's no confusion.
+          (when (and (consp elt) (not (eq elt (last pending-undo-list))))
+            (error "Undoing to some unrelated state"))
+          ;; Undo it all.
+          (save-excursion
+            (while (listp pending-undo-list) (undo-more 1)))
+          ;; Reset the modified cons cell ELT to its original content.
+          (when (consp elt)
+            (setcar elt old-car)
+            (setcdr elt old-cdr))
+          ;; Revert the undo info to what it was when we grabbed the state.
+          (setq buffer-undo-list elt))))))
 
 ;;;; Display-related functions.