GNU bug report logs - #67124
26.3; query-replace Arg out of range with comma option (at end-buffer)

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: gabriele <at> medialab.sissa.it, 67124 <at> debbugs.gnu.org
Subject: bug#67124: 26.3; query-replace Arg out of range with comma option (at end-buffer)
Date: Thu, 16 Nov 2023 13:01:27 -0500

>> > What are you trying to understand?
>> 
>> Why you're saying that in
>> 
>>     ;; `replace-match' leaves point at the end of the replacement text,
>>     ;; so move point to the beginning when replacing backward.
>>     (when backward (goto-char (nth 0 match-data)))
>> 
>> it is not true that
>> 
>>     and (nth 0 match-data) == (match-beginning 0), no?
>
> Because of markers vs positions, as I've tried to explain.  The
> difference is minor, of course.

But `goto-char` doesn't care about that difference, and no buffer will
be changed between the time we call `match-data` (thus creating the
markers) and the time we use those markers, so going through markers is
just extra work for no benefit.

IOW, I still don't understand how "markers vs positions" is relevant in

    (when backward (goto-char (nth 0 match-data)))

>> > What my kludge did is simply use a marker, so the adjusted position is
>> > not clobbered.
>> 
>> I don't see that.  E.g. if you change your code from
>> 
>>     (set-match-data (list (car match-data) (nth 1 (match-data))))
>> to
>>     (set-match-data (list (car match-data) (nth 1 (match-data t))))
>> 
>> it fixes the problem just as well, AFAICT.
>
> Yes, but match-data (the function) returns updated positions, which
> behave like markers across the replace-match call.

But the positions have already been updated.  So

    (match-data t)

would also return those updated positions, even though it doesn't
use markers.


        Stefan

Previous Next

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