possible bug in M-/ (dabbrev-expand)

possible bug in M-/ (dabbrev-expand)

[Dieter Wilhelm]

The following message is a courtesy copy of an article
that has been posted to gmane.emacs.devel as well.

Hi

I deemed it an especially good idea to have function which is
searching something in a buffer when there are changes to the content.
(GNU Emacs 22.0.95.1 (i486-pc-linux-gnu, GTK+ Version 2.8.20) of
2007-03-02 on pacem, modified by Debian.)

When I install such a function in the following way (for example in
the *scratch* buffer):

   $ emacs -Q -D 

   (defun bla ( &optional a b c) ;dummy variables
     (interactive)
     (save-excursion
       (re-search-forward "a" nil 'noerror)))

   (add-hook 'after-change-functions 'bla nil t)

and I try to M-/ something at the buffer beginning, the cursor does
not remain after the expansion but skips somewhere into the buffer.

I'm not sure whether this is a bug of M-/ or this is just a stupid
approach to have such an functionality after a buffer change?  It
would be nice if you could give me some advice before I submit a
possibly unnecessary bug report.

-- 
    Best wishes

    H. Dieter Wilhelm
    Darmstadt, Germany

Re: possible bug in M-/ (dabbrev-expand)

[Stefan Monnier]

>    (defun bla ( &optional a b c) ;dummy variables
>      (interactive)
>      (save-excursion
>        (re-search-forward "a" nil 'noerror)))

>    (add-hook 'after-change-functions 'bla nil t)

You probably need to save-match-data as well.


        Stefan

Re: possible bug in M-/ (dabbrev-expand)

[Dieter Wilhelm]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>>    (defun bla ( &optional a b c) ;dummy variables
>>      (interactive)
>>      (save-excursion
>>        (re-search-forward "a" nil 'noerror)))
>
>>    (add-hook 'after-change-functions 'bla nil t)
>
> You probably need to save-match-data as well.
>

Yes you are right, thank you very much.

-- 
    Best wishes

    H. Dieter Wilhelm
    Darmstadt, Germany