bug#25216: 26.0.50 [regression]; Curly quotes are not found in some sizes of ‘Terminus’ font

[Eli Zaretskii]

> From: Dmitry Alexandrov <321942@gmail.com>
> Cc: larsi@gnus.org,  25216@debbugs.gnu.org
> Date: Wed, 20 Nov 2019 18:01:48 +0300
> 
> Eli Zaretskii <eliz@gnu.org> wrote:
> >> > There was no response to this -- was any further progress made?
> >> 
> >> On my side: sorry, no.  I am fine with the workaround:
> >> 
> >>    Emacs.fontBackend: xft
> >> 
> >> (in ~/.Xresources).
> >
> > Could you try the master branch, after making sure you have HarfBuzz 
> > installed?  The xft font backend is going to be much less important 
> > starting with Emacs 27, so I'd like to know whether this problerm exists 
> > with HarfBuzz
> 
> Yes, the problem is still here, symptoms are the same, except that Terminus 
> is now loaded via harfbuzz:
> 
>       xfthb:-xos4-Terminus-normal-normal-normal-*-18-*-*-*-c-100-iso10646-1
>          ^^
> 
> The same workaround works as well:
> 
>       Emacs.fontBackend: xfthb

I've built the latest version 4.48 of the Terminus font on MS-Windows
and tried it with Emacs 27.  I couldn't reproduce the problem reported
with the xft or xfthb font backends: no matter what size of the font I
tried, the curly quote characters came from the same font.  I do see
that, since this font is bitmapped, i.e. not TrueType, Emacs on
Windows uses the GDI font backend to display it, not the default
HarfBuzz backend.

So I think what you see is something specific to the libxft2 library.
And since this discussion identified at least 2 workarounds: either
customize the fontset, or force the single xft backend in .Xresources,
I think this bug can be closed now.

Thanks.