bug#25945: Emacs aborts while calling FT_Load_Glyph

[Eli Zaretskii <eliz@gnu.org>]

> Date: Fri, 03 Mar 2017 08:04:29 +0100 (CET)
> From: Werner LEMBERG <wl@gnu.org>
> 
> For me, Emacs aborts at ftfont.c:1550 while `mew' tries to display an
> e-mail.
> 
>   1549  if (FT_Load_Glyph (ft_face, g->g.code, FT_LOAD_DEFAULT) != 0)
>   1550    emacs_abort ();
> 
> Examining `ft_face' and `g->g.code' I see that the font in question is
> `Padauk Book Bold' (PadaukBook-Bold.ttf), glyph 376.  Examining this
> font further with `ftview' I see that bytecode of this font is broken,
> and that the font can only be displayed successfully without bytecode.
> [This is version 3.002 of the font, taken from the current TeXLive
> repository.]
> 
> I think there is no reason that Emacs aborts for such broken fonts.
> Instead I suggest that (a) Emacs tries to load the glyph again without
> hinting, and (b) if that fails, it should display a missing glyph,
> using the standard rectangle with hex digits in it.
> 
> New code for (a) is quite simple:
> 
>   if (FT_Load_Glyph (ft_face, g->g.code, FT_LOAD_DEFAULT) != 0)
>     if (FT_Load_Glyph (ft_face, g->g.code, FT_LOAD_NO_HINTING) != 0)
>       ...

Thanks, I've now pushed this change to the Emacs master branch, and
I'm marking this bug done.