Thank you for your help.

I cannot reproduce the error in my computer's original version of Emacs,
22.1.1. I don't know why.

What OS and Tex version did you use when trying to replicate the error?

If the error cannot be replicated on a computer using the latest versions
of Emacs and MacTex, neither installed with Homebrew, then I agree that
Homebrew is somehow causing the issue.

Best regards,
Theodore Ehrenborg

Den lör 20 juli 2019 kl 05:59 skrev Eli Zaretskii <eliz@gnu.org>:

> tags 36696 unreproducible
> thanks
>
> > From: Theodore Ehrenborg <theodore.ehrenborg@gmail.com>
> > Date: Tue, 16 Jul 2019 16:22:44 -0400
> >
> > Type emacs -Q
> > Use C-x C-f to open a new file called test.tex
> > Type the following three lines in test.tex:
> > \foo
> > foo
> > foo
> > (The first line is '\foo', not 'foo')
> > Then go to the beginning of the file with M-<
> > and use M-% to begin query-replace
> > Try to replace 'foo' with 'foo'.
> > When prompted for the first line,
> > type 'y' to replace.
> > Then emacs returns an error:
> > Args out of range: #<buffer test.tex>, 0, 1
> >
> > I'm using the most recent installation of MacTex and emacs.
> > Both were installed with Homebrew.
>
> I cannot reproduce this in Emacs 26.2, 26.2.90, and 27 built from
> sources.
>
> Maybe it's specific to MacTex and Emacs installed with Homebrew.
>