bug#16457: 24.3.50; crash rendering Arabic Uthmani script

[Eli Zaretskii]

> Date: Thu, 16 Jan 2014 14:07:56 +0400
> From: Dmitry Antipov <dmantipov@yandex.ru>
> CC: Eli Zaretskii <eliz@gnu.org>, Kenichi Handa <handa@gnu.org>
> 
> On 01/16/2014 12:01 PM, Dmitry Antipov wrote:
> 
> > I'm not familiar with composition sequences in detail, but there is a hint.
> 
> And there is one more hint: with revision 116000 reverted, this crash goes 
> away.

I'd prefer to fix this bug without reintroducing another one ;-)