Re: Crash with --enable-checking and some glyphs

[Gregory Heytings]

> > I very much doubt that this is the root cause of this bug.
>
> What do you mean by "this"?

"This" means the absence of the "if (it->ascent < 0) it->ascent = 0;" and 
" if (it->descent < 0) it->descent = 0;" in that branch of the function. 
Indeed adding such limitations fixes the problem, but there is apparently 
another bug elsewhere that remains unfixed, and that could pop up later in 
a different form.

> Since the fonts are identical, the root cause could be in the font 
> backend (which is not our code) or maybe elsewhere.

The fonts are identical indeed, but the font backends are also identical. 
So the problem is likely not in the font backends.

> You are welcome to investigate further

I'll do that (if Lars agrees to answer my queries, because ATM I cannot 
reproduce the problem locally).