bug#42904: [PATCH] Non-Unicode frame title crashes Emacs on macOS

[Alan Third <alan@idiocy.org>]

On Tue, Aug 18, 2020 at 01:48:10PM +0200, Mattias Engdegård wrote:
> 18 aug. 2020 kl. 10.43 skrev Alan Third <alan@idiocy.org>:
> > Anyway, as I understand it the internal representation of NS strings
> > are UTF-16, so the conversion through UTF-8 seems a bit of a waste if
> > we can go direct.
> 
> Maybe, but the conversion to UTF-16 then has to be done on the Emacs
> side instead, probably less efficiently than in the NS libs. It's
> probably a wash.
> 
> Anyway, here is an alternative patch using your method. Tell us what
> you think.

Looks good to me. The only thought I have is that perhaps we should
consider extending NSString to handle these lisp strings rather than
making it a separate function? We could provide a method to convert to
a lisp string as well, although that's not as complex.

I believe using categories would do it without us having to create a
new EmacsString class or similar.

I don't know if this is worth it because I don't know if we really
need these clean conversions elsewhere, but the neatness of

    newStr = [NSString withLispObject:str];

appeals. :)
-- 
Alan Third