* buffers.texi (Buffer Modification): Document

buffer-chars-modified-tick.

lispref/ChangeLog

@@ -1,3 +1,8 @@
+2006-09-01  Chong Yidong  <cyd@stupidchicken.com>
+
+	* buffers.texi (Buffer Modification): Document
+	buffer-chars-modified-tick.
+
 2006-08-31  Richard Stallman  <rms@gnu.org>
 
 	* modes.texi (Syntactic Font Lock): Mention specific faces once again.

lispref/buffers.texi

@@ -573,7 +573,6 @@ Don't use this function in programs, since it prints a message in the
 echo area; use @code{set-buffer-modified-p} (above) instead.
 @end deffn
 
-@c Emacs 19 feature
 @defun buffer-modified-tick &optional buffer
 This function returns @var{buffer}'s modification-count.  This is a
 counter that increments every time the buffer is modified.  If
@@ -581,6 +580,23 @@ counter that increments every time the buffer is modified.  If
 The counter can wrap around occasionally.
 @end defun
 
+@defun buffer-chars-modified-tick &optional buffer
+This function returns @var{buffer}'s character-change modification-count.
+Changes to text properties leave this counter unchanged; however, each
+time text is inserted or removed from the buffer, the counter is reset
+to the value that would be returned @code{buffer-modified-tick}.
+By comparing the values returned by two @code{buffer-chars-modified-tick}
+calls, you can tell whether a character change occurred in that buffer
+in between the calls.  If @var{buffer} is @code{nil} (or omitted), the
+current buffer is used.
+@end defun
+
+This function returns @var{buffer}'s modification-count.  This is a
+counter that increments every time the buffer is modified.  If
+@var{buffer} is @code{nil} (or omitted), the current buffer is used.
+The counter can wrap around occasionally.
+@end defun
+
 @node Modification Time
 @comment  node-name,  next,  previous,  up
 @section Comparison of Modification Time