Emacs 27.1 forces a very ugly font for Cyrillic characters and I can't override it.

Emacs 27.1 forces a very ugly font for Cyrillic characters and I can't override it.

[Nikolay Kudryavtsev]

Hello.

Being rather operative with the new releases, I've finally decided to 
upgrade to 27.1 from 26.2. And here's what I ran into:

In my init I have:

(add-to-list 'default-frame-alist '(font . "Liberation Mono-10"))

This forces Liberation Mono font for all frames. Or would do so before 
27.1. But now all of the Cyrillic characters get displayed in MS Gothic, 
which is a very ugly font.

I've tried to test an assumption that maybe the font-backend is 
responsible for font selection and now the harfbuzz is the default for 
me. But forcing uniscribe again didn't help.

Any advice?

-- 
Best Regards,
Nikolay Kudryavtsev

Re: Emacs 27.1 forces a very ugly font for Cyrillic characters and I can't override it.

[Eli Zaretskii]

> From: Nikolay Kudryavtsev <nikolay.kudryavtsev@gmail.com>
> Date: Sat, 13 Mar 2021 15:05:13 +0300
> 
> Being rather operative with the new releases, I've finally decided to 
> upgrade to 27.1 from 26.2. And here's what I ran into:
> 
> In my init I have:
> 
> (add-to-list 'default-frame-alist '(font . "Liberation Mono-10"))
> 
> This forces Liberation Mono font for all frames. Or would do so before 
> 27.1. But now all of the Cyrillic characters get displayed in MS Gothic, 
> which is a very ugly font.

You are on Windows 10, right?

What does the below produce?

  M-: (getenv "LANG") RET

> I've tried to test an assumption that maybe the font-backend is 
> responsible for font selection and now the harfbuzz is the default for 
> me. But forcing uniscribe again didn't help.

No, the fact that we use HarfBuzz now is not related to this, I think.
Font selection is largely independent of the font backend.

Re: Emacs 27.1 forces a very ugly font for Cyrillic characters and I can't override it.

[Nikolay Kudryavtsev]

Yes, Windows 10.

(getenv "LANG"): "RUS"

-- 
Best Regards,
Nikolay Kudryavtsev

Re: Emacs 27.1 forces a very ugly font for Cyrillic characters and I can't override it.

[Eli Zaretskii]

> From: Nikolay Kudryavtsev <nikolay.kudryavtsev@gmail.com>
> Date: Sat, 13 Mar 2021 19:02:24 +0300
> 
> Yes, Windows 10.
> 
> (getenv "LANG"): "RUS"

Then this is not the problem I'm aware of.  The one I saw caused the
above to return "ZZZ" (meaning unrecognized language), and the
upcoming Emacs 27.2 will have it fixed.

What happens if you start Emacs as "emacs -Q"? does the problem still
exist, and if so, what does the above yield then?

Re: Emacs 27.1 forces a very ugly font for Cyrillic characters and I can't override it.

[Nikolay Kudryavtsev]

Yes, still happens with Emacs -Q too. And it's "RUS" again.

Also I've just tried the emacs-27.1.91-x86_64.zip 
<https://alpha.gnu.org/gnu/emacs/pretest/windows/emacs-27/emacs-27.1.91-x86_64.zip> 
pretest binary, same problem.

-- 
Best Regards,
Nikolay Kudryavtsev

Re: Emacs 27.1 forces a very ugly font for Cyrillic characters and I can't override it.

[Eli Zaretskii]

> From: Nikolay Kudryavtsev <nikolay.kudryavtsev@gmail.com>
> Date: Sat, 13 Mar 2021 19:44:15 +0300
> 
> Yes, still happens with Emacs -Q too. And it's "RUS" again.

But in "emacs -Q" the default font is not "Liberation Mono-10", it's
Courier New.

> Also I've just tried the emacs-27.1.91-x86_64.zip pretest binary, same problem.

The bug was fixed after that pretest was made.

Anyway, it sounds like a different problem, sorry.  Someone with
access to that system will have to debug it.  All I can suggest is to
customize your fontset to force that font with Cyrillic script.

Re: Emacs 27.1 forces a very ugly font for Cyrillic characters and I can't override it.

[Eli Zaretskii]

> Date: Sat, 13 Mar 2021 18:59:46 +0200
> From: Eli Zaretskii <eliz@gnu.org>
> 
> Anyway, it sounds like a different problem, sorry.  Someone with
> access to that system will have to debug it.  All I can suggest is to
> customize your fontset to force that font with Cyrillic script.

As the last resort, try evaluating this immediately after entering
"emacs -Q":

 M-: (w32-add-charset-info "iso8859-5" 'w32-charset-russian 28595) RET

Then type something in Russian and see if that helps.

Re: Emacs 27.1 forces a very ugly font for Cyrillic characters and I can't override it.

[Eli Zaretskii]

> From: Nikolay Kudryavtsev <nikolay.kudryavtsev@gmail.com>
> Date: Sat, 13 Mar 2021 21:27:47 +0300
> 
> This indeed helped.

Then Emacs 27.2 will fix this after all (it includes that in
w32-fns.el, and so does that by default).

> I can probably bisect the main branch to find the cause. Does your 
> famous crystal ball have any suggestions of what change may have caused it?

Sorry, no.  If you can afford bisecting, I'd be interested to know
which change caused this.

Thanks.

Re: Emacs 27.1 forces a very ugly font for Cyrillic characters and I can't override it.

[Nikolay Kudryavtsev]

By bisecting I've traced the source of the problem to d12e5d003d, which 
is the portable dumper integration commit. Can't really go further than 
that since studying that code would probably result in me worshiping 
some Lovecraftean god.

I've tested the 27.2 release. It's better, in that it does not force Ms 
Gothic at the very least, but there seems to be still a problem in that 
overriding the default font using the default-frame-alist does not seem 
to work and you're stuck with Courier New. Changing the font in the menu 
works.

Re: Emacs 27.1 forces a very ugly font for Cyrillic characters and I can't override it.

[Nikolay Kudryavtsev]

Never mind the second part of my previous letter, doing (add-to-list 
'default-frame-alist '(font . "Liberation Mono-10")) works fine on 27.2. 
It's something I broke myself while trying to debug.

Re: Emacs 27.1 forces a very ugly font for Cyrillic characters and I can't override it.

[Eli Zaretskii]

> From: Nikolay Kudryavtsev <nikolay.kudryavtsev@gmail.com>
> Date: Fri, 26 Mar 2021 16:34:56 +0300
> 
> By bisecting I've traced the source of the problem to d12e5d003d, which 
> is the portable dumper integration commit. Can't really go further than 
> that since studying that code would probably result in me worshiping 
> some Lovecraftean god.

I don't think d12e5d003d is relevant, I think this problems was always
there.  It just started happening with the newer versions of Windows.

Emacs 27.2 should fix that.

Re: Emacs 27.1 forces a very ugly font for Cyrillic characters and I can't override it.

[Nikolay Kudryavtsev]

I'm 100% certain d12e5d003d is relevant. I've been using Windows 10 
pretty much since it was originally released without running into that 
particular problem. I've also tested both d12e5d003d and the last good 
version(2a3bd6798e) on another Win10 machine I have. The last good 
version and everything older works fine.

Re: Emacs 27.1 forces a very ugly font for Cyrillic characters and I can't override it.

[Eli Zaretskii]

> From: Nikolay Kudryavtsev <nikolay.kudryavtsev@gmail.com>
> Date: Fri, 26 Mar 2021 18:51:10 +0300
> 
> I'm 100% certain d12e5d003d is relevant. I've been using Windows 10 
> pretty much since it was originally released without running into that 
> particular problem. I've also tested both d12e5d003d and the last good 
> version(2a3bd6798e) on another Win10 machine I have. The last good 
> version and everything older works fine.

If so, then there was something in the pre-dumper code that masked the
real bug, which was fixed in Emacs 27.2.  The bug was that Emacs
didn't consider the ISO 8859-5 character set as a Cyrillic character
set, and because of that rejected fonts that declared support for
Cyrillic (on MS-Windows).

Re: Emacs 27.1 forces a very ugly font for Cyrillic characters and I can't override it.

[Nikolay Kudryavtsev]

That's probably the correct explanation.