[Emacs-bug-tracker] bug#7946: closed (Referring to a marker changes Emacs' behaviour.)

[GNU bug Tracking System]

Your message dated Wed, 02 Feb 2011 10:54:56 -0500
with message-id <address@hidden>
and subject line Re: bug#7946: Referring to a marker changes Emacs' behaviour.
has caused the GNU bug report #7946,
regarding Referring to a marker changes Emacs' behaviour.
to be marked as done.

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-- 
7946: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=7946
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--- Begin Message --- Subject: Referring to a marker changes Emacs' behaviour. Date: Mon, 31 Jan 2011 14:45:43 +0800 Hi,

I found an issue where evaluating this line or not causes Emacs behaviour change:

(format "%s" marked-point)

"marked-point" is a marker.  The bug was found on NTEmacs 23.2.1, reproed on CVS NTEmacs 20110111, and Stephen Berman confirmed it on GNU Emacs 24.0.50.1

(i686-pc-linux-gnu, GTK+ Version 2.20.1) of 2011-01-13 on escher

"rebox2_bug.el" is attached to this message.

Repro-steps:

1. emacs -Q rebox2_bug.el
2. M-x eval-current-buffer
3. C-x b<enter> ;; switch to "*scratch*"
4. M-x rebox-mode
5. M-<
6. SPC,SPC ;; space twice
7. C-aC-aC-aC-a ;; notice that the point is stuck at 6
8. C-xb<enter> ;; switch to "rebox2_bug.el
9. M-g g 1714
10. C-d ;; uncomment the hack workaround the bug
11. C-M-x ;; reevaluated the function 
12. C-x b<enter> ;; switch to "*scratch*"
13. C-aC-aC-aC-a ;; notice that the cursor switches between 1 and 6

--
Le

rebox2_bug.el
Description: Binary data

--- End Message ---

> --- Begin Message ---
>
>
>
> Subject: 
>
> Re: bug#7946: Referring to a marker changes Emacs' behaviour.
>
>
>
>
> Date: 
>
> Wed, 02 Feb 2011 10:54:56 -0500
>
>
>
>
> User-agent: 
>
> Gnus/5.13 (Gnus v5.13) Emacs/24.0.50 (gnu/linux)
>
>
>
>
> > I found an issue where evaluating this line or not causes Emacs behaviour
> > change:
>
> > (format "%s" marked-point)
>
> The patch below appears to fix the problem for me.  I've installed it in
> the emacs-23 branch.
>
> The problem was that current-column uses a cache to try and speed up
> some cases, and the cache was not flushed when exiting
> a save-restriction.  The workaround you used works because `set-buffer'
> flushes the cache and `format' uses set-buffer internally.
>
>
>         Stefan
>
>
> === modified file 'src/editfns.c'
> --- src/editfns.c       2011-01-02 23:50:46 +0000
> +++ src/editfns.c       2011-02-02 15:45:27 +0000
> @@ -3347,6 +3347,9 @@
>         }
>      }
>  
> +  /* Changing the buffer bounds invalidates any recorded current column.  */
> +  invalidate_current_column ();
> +
>    if (cur)
>      set_buffer_internal (cur);
>  
>
>
>
> --- End Message ---