(mark-word): New arg ALLOW-EXTEND

enables the feature to extend the existing region.

1 files changed, 28 insertions, 10 deletions

diff --git a/lisp/simple.el b/lisp/simple.el
index 65a667f482e..f5bc8a40fa6 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -1524,17 +1524,33 @@ is not *inside* the region START...END."
              '(0 . 0)))
     '(0 . 0)))
 
+(defvar undo-extra-outer-limit nil
+  "If non-nil, an extra level of size that's ok in an undo item.
+We don't ask the user about truncating the undo list until the
+current item gets bigger than this amount.")
+(make-variable-buffer-local 'undo-extra-outer-limit)
+
 ;; When the first undo batch in an undo list is longer than undo-outer-limit,
 ;; this function gets called to ask the user what to do.
 ;; Garbage collection is inhibited around the call,
 ;; so it had better not do a lot of consing.
 (setq undo-outer-limit-function 'undo-outer-limit-truncate)
 (defun undo-outer-limit-truncate (size)
-  (if (let (use-dialog-box)
-        (yes-or-no-p (format "Buffer %s undo info is %d bytes long; discard it? "
-                             (buffer-name) size)))
-      (progn (setq buffer-undo-list nil) t)
-    nil))
+  (when (or (null undo-extra-outer-limit)
+            (> size undo-extra-outer-limit))
+    ;; Don't ask the question again unless it gets even bigger.
+    ;; This applies, in particular, if the user quits from the question.
+    ;; Such a quit quits out of GC, but something else will call GC
+    ;; again momentarily.  It will call this function again,
+    ;; but we don't want to ask the question again.
+    (setq undo-extra-outer-limit (+ size 50000))
+    (if (let (use-dialog-box)
+          (yes-or-no-p (format "Buffer %s undo info is %d bytes long; discard it? "
+                               (buffer-name) size)))
+        (progn (setq buffer-undo-list nil)
+               (setq undo-extra-outer-limit nil)
+               t)
+      nil)))
 
 (defvar shell-command-history nil
   "History list for some commands that read shell commands.")
@@ -3573,15 +3589,17 @@ With argument, do this that many times."
   (interactive "p")
   (forward-word (- (or arg 1))))
 
-(defun mark-word (&optional arg)
+(defun mark-word (&optional arg allow-extend)
   "Set mark ARG words away from point.
 The place mark goes is the same place \\[forward-word] would
 move to with the same argument.
-If this command is repeated or mark is active in Transient Mark mode,
+Interactively, if this command is repeated
+or (in Transient Mark mode) if the mark is active, 
 it marks the next ARG words after the ones already marked."
-  (interactive "P")
-  (cond ((or (and (eq last-command this-command) (mark t))
-             (and transient-mark-mode mark-active))
+  (interactive "P\np")
+  (cond ((and allow-extend
+              (or (and (eq last-command this-command) (mark t))
+                  (and transient-mark-mode mark-active)))
          (setq arg (if arg (prefix-numeric-value arg)
                      (if (< (mark) (point)) -1 1)))
          (set-mark