bug#21822: 25.0.50; emacs_backtrace.txt

[Eli Zaretskii <eliz@gnu.org>]

> Date: Wed, 4 Nov 2015 09:11:00 -0800 (PST)
> From: Drew Adams <drew.adams@oracle.com>
> Cc: lekktu@gmail.com, jwiegley@gmail.com, 21822@debbugs.gnu.org
> 
> > Do you have BabelMap installed?  If not, could you install it, and
> > then see which fonts cover this character on your machine?  Here, I
> > have the following ones:
> > 
> >   Arial Unicode MS
> >   Code2000
> >   FreeSans
> >   FreeSerif
> >   Lucida Sans
> >   Mangal
> > 
> > and Emacs actually chooses the last one when it displays this
> > character.
> 
> Dunno what BabelMap is

It's a nice program that can display any character you want, and also
can analyze font coverage on your system.

  http://www.babelstone.co.uk/Software/BabelMap.html

> or why I would want to install it.

It's the best way I know of to find out which fonts Emacs might have
tried to use for displaying that character.  Armed with that
knowledge, I might be able to reproduce your crash and fix it.

> Shouldn't it be enough to know that Emacs crashed when given
> a char that it cannot show in the given font?  I didn't choose
> the font - emacs -Q chose it.

The fonts Emacs choses depend on the fonts available on your system.
I cannot know which fonts you have that cover this character, and
Emacs doesn't crash for me (nor for Juanma) when we try your recipe.

Assuming you do want the reason for this crash be identified and
fixed, please help us by providing the information I asked for.