Subject: Re: bug#79200: 31.0.50; Duplicated elements for '#<marker at' in buffer-undo-list

From: Gerd Möllmann <[email-masked]>
Date: Tue, 12 Aug 2025 16:40:22 +0200

Gerd Möllmann <[email-masked]> writes:

> Gerd Möllmann <[email-masked]> writes:
>
>> Let's see what the others think about such a plan. 
>
> Please find attached a patch which gives an impression what that could
> look like. Entirely untested of course, plus for my Emacs, which has a
> different marker implementation, plus I'm not certain which other Lisp
> or C could be affected by such a change.

Had the DEFSYM wrong. With that a simple undo works in emacs -q. YMMV.

>From 988d930c8cfe1fe5404bc28d542eab36df4edabe Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gerd=20M=C3=B6llmann?= <[email-masked]>
Date: Tue, 12 Aug 2025 16:37:33 +0200
Subject: [PATCH] ; Fix DEFSYM

* src/undo.c (syms_of_undo): adjust_marker -> adjust-marker.
---
 src/undo.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/undo.c b/src/undo.c
index 9f07ac5d4b6..8702d937ed5 100644
--- a/src/undo.c
+++ b/src/undo.c
@@ -432,7 +432,7 @@ syms_of_undo (void)
 
   /* Marker for function call undo list elements.  */
   DEFSYM (Qapply, "apply");
-  DEFSYM (Qadjust_marker, "adjust_marker");
+  DEFSYM (Qadjust_marker, "adjust-marker");
 
   pending_boundary = Qnil;
   staticpro (&pending_boundary);
-- 
2.50.1