GNU bug report logs - #46982
28.0.50; after-change-functions in an indirect buffer are not called if the change is done while base buffer is active (and vice versa)

Previous Next

Full log

View this message in rfc822 format

From: Stefan Monnier <monnier <at> iro.umontreal.ca>
To: Eli Zaretskii <eliz <at> gnu.org>
Cc: 46982 <at> debbugs.gnu.org, Ihor Radchenko <yantar92 <at> gmail.com>
Subject: bug#46982: 28.0.50; after-change-functions in an indirect buffer are not called if the change is done while base buffer is active (and vice versa)
Date: Wed, 29 Jun 2022 11:19:37 -0400

>> >> It might be a good thing to mention somewhere around
>> >> `clone-buffer`, yes.  I'll see what I can come up with.
>> > Hmm... we don't document `clone-buffer` anywhere that I can see.
>> > Any suggestion where I could put that kind of info?
>> `clone-indirect-buffer' I think. For example, in 19.6 Indirect Buffers
>> section of the manual.
> Yes, there, please.

How does the patch below sound to you?


        Stefan


diff --git a/doc/emacs/buffers.texi b/doc/emacs/buffers.texi
index 94e9d2760ec..c07f3990ee8 100644
--- a/doc/emacs/buffers.texi
+++ b/doc/emacs/buffers.texi
@@ -616,10 +616,11 @@ Indirect Buffers
 
   The text of the indirect buffer is always identical to the text of its
 base buffer; changes made by editing either one are visible immediately
-in the other.  But in all other respects, the indirect buffer and its
+in the other.  ``Text'' here includes both the characters and their text
+properties.  But in all other respects, the indirect buffer and its
 base buffer are completely separate.  They can have different names,
 different values of point, different narrowing, different markers,
-different major modes, and different local variables.
+different overlays, different major modes, and different local variables.
 
   An indirect buffer cannot visit a file, but its base buffer can.  If
 you try to save the indirect buffer, that actually works by saving the
@@ -649,6 +650,14 @@ Indirect Buffers
 When this hook runs, the newly created indirect buffer is the current
 buffer.
 
+Note: When a modification is made to the text of a buffer, the
+modification hooks are only run in the base buffer, because most of
+the functions on those hooks are not prepared to work correctly in
+indirect buffers.  So if you need a modification hook function in an
+indirect buffer, you need to manually add that function to the hook
+@emph{in the base buffer} and then make the function operate in the
+desired indirect buffer.
+
 @node Buffer Convenience
 @section Convenience Features and Customization of Buffer Handling
 

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.