Subject: Re: bug#44113: 28.0.50; crash with cairo and Noto Sans Javanese font

From: Stephen Berman <[email-masked]>
Date: Wed, 21 Oct 2020 15:25:13 +0200

On Wed, 21 Oct 2020 15:00:45 +0200 Robert Pluim <[email-masked]> wrote:

>>>>>> On Wed, 21 Oct 2020 14:22:13 +0200, Stephen Berman
> <[email-masked]> said:
>
>     Stephen> On Wed, 21 Oct 2020 12:12:00 +0200 Stephen Berman
>     Stephen> <[email-masked]> wrote:
>     >> I installed NotoSansJavanese-Regular.ttf and when I type `C-h h' to view
>     >> the Javanese script, Emacs immediately crashes.  It also crashes when I
>     >> just try to insert a character from that script, e.g. `C-x 8 RET #xa9b2
>     >> RET'.  I've attached the backtrace from gdb produced from the latter.
>     >> Emacs also crashes when trying to display a character from the Balinese
>     >> script with NotoSansBalinese-Regular.ttf installed.  The crashes do not
>     >> happen in emacs-27 built without cairo, but characters from the Javanese
>     >> and Balinese scripts are displayed there as tofu, as they are in Firefox
>     >> (e.g. https://en.wikipedia.org/wiki/Javanese_script), so maybe the fonts
>     >> are buggy; and indeed, when I uninstall them Emacs built with cairo does
>     >> not crash and the characters are displayed as tofu.
>
>     Stephen> It seems those fonts are indeed buggy: I just installed
>     Stephen> NotoSansJavanese-Regular.ttf from
>     Stephen> https://github.com/googlefonts/noto-fonts and with it the Javanese
>     Stephen> script sample in etc/HELLO displays fine both in Emacs from master built
>     Stephen> with cairo and in emacs-27 with xft (and the Javanese script Wikipedia
>     Stephen> page also displays fine in Firefox; the googlefonts repository does not
>     Stephen> contain NotoSansBalinese-Regular.ttf but instead
>     Stephen> NotoSerifBalinese-Regular.ttf, which I also installed and with it the
>     Stephen> Balinese characters in the Wikipedia page also display fine).
>
>     >> But it would be
>     >> better for Emacs with cairo not to crash with a buggy font, if possible.
>
>     Stephen> That would still be good, but if it's not practically feasible, I guess
>     Stephen> this bug should just be closed.
>
>     Stephen> Steve Berman
>
> Looking at the backtrace, this could be another manifestation of
> bug#41627. That bug has a patch, would it be possible to try it?

I assume you mean Pip Cet's second patch, in
<CAOqdjBc+x65eSjsvgKv=[email-masked]>?  I
applied that and rebuilt from master, and reinstalled the problematic
NotoSansJavanese-Regular.ttf font, and now with it displaying etc/HELLO
does not crash Emacs, and the Javanese characters are displayed as tofu.
So this is another datapoint in favor of installing that patch.  Thanks
for the pointer.

Steve Berman