bug#51716: 29.0.50; [PATCH] Expose xwidget navigation history to Lisp code

[Eli Zaretskii]

> From: Po Lu <luangruo@yahoo.com>
> Cc: 51716@debbugs.gnu.org
> Date: Sun, 14 Nov 2021 08:18:39 +0800
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > Sorry, I don't understand: the above produces strings that will be
> > used by Emacs Lisp.  So UTF-8 is not relevant; the question is whether
> > the string that comes from WebKitGTK can include non-ASCII characters.
> > If it can, we need to decode it, e.g. by decode_string_utf_8 (can
> > these strings include byte sequences that aren't valid UTF-8?).
> 
> Ah, they cannot include byte sequences that aren't valid UTF-8.

If they cannot include invalid UTF-8, then using decode_string_utf_8
is what you need to do.  You cannot use those strings directly in
Lisp, because they will be unibyte strings.  IOW, using build_string
there is incorrect, you need to use make_unibyte_string and
decode_string_utf_8 instead.  build_string is correct only for
plain-ASCII strings.