On Thu, Jul 01, 2021 at 10:13:04AM +0300, Eli Zaretskii wrote:
> It should work, although I'd prefer writing such code the other way
> around: first create an uninitialized Lisp string (with
> make_uninit_multibyte_string or make_uninit_string), then copy the
> bytes while making the conversions.  The reason for this preference is
> that you could then make sure the produced string has the same
> multibyte-ness as the original, whereas the way you did it relies on
> whatever build_string decides, which is not necessarily the same.

Thanks. I think the attached is doing what you suggested.
-- 
Alan Third