Bug#1028643: fontconfig: 2.14.1-3 greatly changes font rendering

[Sébastien Villemot]

On Sat, 14 Jan 2023 06:56:53 +0100 Christoph Anton Mitterer <cale...@scientia.org> wrote:
> Package: fontconfig
> Version: 2.14.1-3
> Severity: important

> After upgrading from 2.13.1-4.5 to 2.14.1-3 the font rendering looks
> noticebly different (and IMO worse).
>
> Attached are some example images (before/after). It's always the same
> window (i.e. nothing was closed or so, but aptitude changed a bit
> because of the downgrading), just fontconfig was upgraded/downgraded.
>
> AFAICT not only the line spaces are different, but also the font
> changed (look at the zeros).

As far as I can tell, it’s not that the font rendering has changed, but
that the default monospace font has changed (it was previously DejaVu
Mono Book on my system, now it’s Noto Sans Mono; see the output of “fc-
match monospace”).

I don’t know if this change is intended. Note that it in particular it
impacts the default GNOME configuration.

--
⢀⣴⠾⠻⢶⣦⠀  Sébastien Villemot
⣾⠁⢠⠒⠀⣿⡁  Debian Developer
⢿⡄⠘⠷⠚⠋⠀  https://sebastien.villemot.name
⠈⠳⣄⠀⠀⠀⠀  https://www.debian.org

[Christoph Anton Mitterer]

Control: severity -1 normal

Hey Sébastien.

On Sat, 2023-01-14 at 15:19 +0100, Sébastien Villemot wrote:
> As far as I can tell, it’s not that the font rendering has changed,
> but
> that the default monospace font has changed (it was previously DejaVu
> Mono Book on my system, now it’s Noto Sans Mono; see the output of
> “fc-
> match monospace”).

Strange, for me - with the old version of fontconfig - it shows:
$ fc-match
Vera.ttf: "Bitstream Vera Sans" "Roman"

(i.e. not DejaVu).

> I don’t know if this change is intended. Note that it in particular
> it
> impacts the default GNOME configuration.

Ah... I think I just realised that the "Monospace" font, which Cinnamon
shows in it's config as the default font for a monospaced font doesn't
seem to be an actual font, but just some alias or whatever default fc
sets?


Not sure how to best deal with this issue - do you think a NEWS.Debian
entry would be appropriate?
I mean changing that can be quite "annoying" to people, if they're very
used to their font and maybe do not even directly notice what's
different, just that something looks strange ;-)

At least personally, I find the increased line space quite ugly for
terminals, etc..


Cheers,
Chris.

[Konomi]

For anyone who is not super happy with this change from DejaVu to Noto
I just did this to revert it:

1. Create a file called /etc/fonts/conf.d/50-prefer-dejavu.conf
2. Add the following:

<fontconfig>
<alias>
<family>monospace</family>
<prefer>
<family>DejaVu Sans Mono</family>
</prefer>
</alias>
<alias>
<family>sans</family>
<prefer>
<family>DejaVu Sans Book</family>
</prefer>
</alias>
<alias>
<family>serif</family>
<prefer>
<family>DejaVu Serif Book</family>
</prefer>
</alias>
</fontconfig>

3. Save the file and run fc-cache -r

I'm not super familiar with how fontconfig works so if anyone who is
could look over this and suggest a better method it would be greatly
appreciated. But this seems to work if you want the old behaviour
back.

[Konomi]

Just to add as an XFCE user this change greatly impacted the look of
my desktop. So while this may be fine for GNOME users, people with
other DEs could be affected by the change.

I also didn't quite get the file correct to revert the change in my
previous email so here's the updated version, as far as I know this
should work correctly.

<fontconfig>
<alias>
<family>monospace</family>
<prefer>
<family>DejaVu Sans Mono</family>
</prefer>
</alias>
<alias>
<family>sans</family>
<prefer>

<family>DejaVu Sans</family>
</prefer>
</alias>
<alias>
<family>sans-serif</family>
<prefer>
<family>DejaVu Sans</family>

</prefer>
</alias>
<alias>
<family>serif</family>
<prefer>

<family>DejaVu Serif</family>
</prefer>
</alias>
</fontconfig>

[Konomi]

This is the upstream change in fontconfig that led to this bug report
[1]. I can't find any reason why Noto is now preferred over DejaVu in
the change or issues.

[1] https://gitlab.freedesktop.org/fontconfig/fontconfig/-/commit/ad70d785974992c569b30108923875e5b5e9dc5e

[Ryan Thoryk]

Yesterday I noticed a substantial change in the interface fonts for my
whole system, I'm running Testing. They appear somewhat clearer, but
don't align properly like the old fonts. I'm using MATE, and it caused
things like titlebars to increase in size. I had noticed rendering
changes with fontconfig in previous years, but this one seems to be a
lot more than just rendering changes.

--
Ryan Thoryk
ry...@thoryk.com
ry...@tliquest.net

[Konomi]

As I kind of rushed the fix for this here is what I am sure should be
the most correct way to fix this issue. If you want to change the
fonts system wide create /etc/fonts/local.conf for your user only
~/.config/fontconfig/fonts.conf and put the following in the file:

<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "urn:fontconfig:fonts.dtd" >
<fontconfig>

<alias>
<family>serif</family>
<prefer>
<family>DejaVu Serif</family>
</prefer>
</alias>
<alias>
<family>sans-serif</family>
<prefer>
<family>DejaVu Sans</family>
</prefer>
</alias>
<alias>

<family>monospace</family>
<prefer>
<family>DejaVu Sans Mono</family>
</prefer>
</alias>

</fontconfig>

The /etc/fonts/conf.d/50-prefer-dejavu.conf file can be removed as
that's not where the config should be located (best practice as far as
I know is the paths in this post). Sorry for the noise and I hope this
helps everyone affected.