bug#17243: 24.3; upcase-word &c. functions partially fail for Coptic

[Eli Zaretskii <eliz@gnu.org>]

> From: "William Parsons" <wbparsons@cshore.com>
> Date: Fri, 11 Apr 2014 16:50:16 -0400
> Cc: wbparsons@cshore.com
> 
> The upcase/downcase/capitalize functions only work for some letters for
> Coptic (Unicode utf-8 encoding).  For example, applying the downcase-word
> function to the following snippet (all in upper case) of Coptic:
> 
> ϨⲒϪⲰϤ
> 
> results in the first, third, & last letters being down-cased, but the 2nd
> and 4th remaining upper-case.
> 
> The Coptic alphabet is in origin an extension of the Greek alphabet, and
> the Unicode encoding is unusual in that it is divided between two code
> blocks, the Greek/Coptic code block (0370), and the Coptic code block (2C80).
> (Confusingly, the Coptic letters that come from Greek reside in the
> Coptic code block, and the purely Coptic letters reside in the Greek
> block.)
> 
> It appears the case functions work for the purely Coptic letters but not
> for the letters derived from Greek.

Thanks, I fixed this in revision 116945 on the emacs-24 branch, so
this bug will be fixed in the upcoming Emacs 24.4 release.