bug#23522: 25.0.93; SEGFAULT when displaying HELLO

[Eli Zaretskii <eliz@gnu.org>]

> From: Michael Welsh Duggan <mwd@md5i.com>
> Cc: mwd@md5i.com,  Kenichi Handa <handa@gnu.org>,  mwd@cert.org,  23522@debbugs.gnu.org
> Date: Fri, 13 May 2016 10:52:31 -0400
> 
> > So the question becomes: where did that value of 'to' come from, and
> > how come its value is bogus?  Can you look at the code before the
> > faulting line and figure that out?
> 
> It's being filled in by mflt_run() at ftfont.c:2646.

Which means either a bug in the library or a bad font.

> >>   xft:-unknown-FreeSerif-normal-normal-normal-*-15-*-*-*-*-0-iso10646-1
> >> by these glyphs:
> >>   [0 3 0 10195 9 0 10 10 0 nil]
> >>   [0 3 2724 2103 10 1 10 10 1 nil]
> >>   [0 3 2759 2132 0 -8 -2 13 -10 [-1 0 0]]
> >
> > So why does Emacs use FreeSerif on this system and Lohit Gujarati on
> > the faulting one? 
> 
> The two systems I have access to are running completely different
> distributions of Linux.  I don't have much control over the packages
> installed on the system on which Emacs breaks.

OK, but are both fonts installed on both systems?

> > Are both fonts installed on both systems?  Is Lohit
> > Gujarati a bad font, by any chance?
> 
> No idea.  How can I find out?

Install the latest version of it?

> > Also, do both systems have the same version of libm17n-flt and m17n-db
> > libraries?
> 
> Almost certainly not.

Then perhaps using a newer version will help?

Anyway, this sounds more and more like a bug in one of the libraries
Emacs uses, so I hope Handa-san will be able to chime in, since he is
one of the maintainers of those libraries.

Thanks.