Re: mm-with-unibyte-current-buffer

[Eli Zaretskii <eliz@gnu.org>]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Date: Mon, 10 May 2010 13:51:27 -0400
> Cc: Katsumi Yamaoka <yamaoka@jpl.org>, ding@gnus.org, emacs-devel@gnu.org
> 
> > Binding the value of enable-multibyte-characters may be a no-no, but
> > _testing_ its value is still possible.  So I see no reason to
> > set-buffer-multibyte unconditionally, because you may already be in a
> > unibyte buffer.
> 
> But calling set-buffer-multibyte with the current value is harmless (it
> checks a returns right away if there's nothing to do; this check might
> even be faster than doing it in Elisp).

That's true, but the unconditional call `(set-buffer-multibyte t)' at
the end of the macro is _not_ harmless, if the buffer was originally a
unibyte one.