From: Alan Mackenzie <acm@muc.de>
Date: Tue, 21 Oct 2008 21:14:04 +0000 (+0000)
Subject: (undo-more): Add comment explaining the operations on pending-undo-list
X-Git-Tag: emacs-pretest-23.0.90~2286
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=b553f6858c6edab5f4e1494272d455adc0d2668e;p=emacs.git

(undo-more): Add comment explaining the operations on pending-undo-list
and buffer-undo-list.
---

diff --git a/lisp/simple.el b/lisp/simple.el
index 7cd321564d9..6ebbd71cdbf 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -1725,6 +1725,9 @@ then call `undo-more' one or more times to undo them."
       (error (concat "No further undo information"
 		     (and undo-in-region " for region"))))
   (let ((undo-in-progress t))
+    ;; Note: The following, while pulling elements off
+    ;; `pending-undo-list' will call primitive change functions which
+    ;; will push more elements onto `buffer-undo-list'.
     (setq pending-undo-list (primitive-undo n pending-undo-list))
     (if (null pending-undo-list)
 	(setq pending-undo-list t))))