Subject: bug#49124: Wdired doesn't like re-search-forward/replace-match

From: Eduardo Ochs <[email-masked]>
Date: Sat, 19 Jun 2021 22:45:25 -0300

On Sat, 19 Jun 2021 at 22:28, Michael Heerdegen
<[email-masked]> wrote:
>
> Eduardo Ochs <[email-masked]> writes:
>
> > Here's how to see the bug in action. Define `foo' by executing this
> > defun:
> >
> >   (defun foo (s e)
> >     "Replace all `a's by `b's in the region."
> >     (interactive "r")
> >     (save-excursion
> >       (save-restriction
> >         (narrow-to-region s e)
> >         (goto-char (point-min))
> >         (while (re-search-forward "a" nil 'noerror)
> >           (replace-match "b" 'fixedcase 'literal)))))
> > [...]
>
> I can reproduce the issue.  The culprit seems to be `narrow-to-region'
> which seems to confuse the functions wdired now installs in the before
> and/or after change hooks (they expect at least complete lines) --
> because this version:
>
> (defun foo (s e)
>   "Replace all `a's by `b's in the region."
>   (interactive "r")
>   (save-excursion
>     (save-restriction
>       ;; (narrow-to-region s e)
>       (goto-char s)
>       (while (re-search-forward "a" e 'noerror)
>         (replace-match "b" 'fixedcase 'literal)))))
>
> works as expected.
>
> I guess we should just temporarily `widen' in these functions.
>
> Michael.

Hi Michael,

Is there a simple way to write a macro called, say,
`wdired-with-narrow-to-filename' that would narrow the buffer to the
editable portion of current line, evaluate some code, and on exit it
would tell wdired to reread the filename in that line, knowing that it
it may have been changed?

  Cheers & possibly thanks in advance =),
    Eduardo Ochs
    http://angg.twu.net/#eev