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

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

[William Parsons]

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.

I realize this is probably not a high-priority item (after all, how many
Emacs users can there be who want to use it for Coptic text?), so if I
can help in fixing this I will be happy to do so.

In GNU Emacs 24.3.1 (i386-portbld-freebsd9.2, GTK+ Version 2.24.22)
 of 2014-03-24 on anukis.local
Windowing system distributor `The X.Org Foundation', version 11.0.10707000
Configured using:
 `configure '--localstatedir=/var' '--without-compress-info'
 '--without-dbus' '--without-gconf' '--with-gif' '--with-gnutls'
 '--without-gsettings' '--with-jpeg' '--with-m17n-flt'
 '--with-imagemagick' '--with-libotf' '--with-png'
 '--with-toolkit-scroll-bars' '--with-sound' '--with-rsvg'
 '--with-sync-input' '--with-tiff' '--with-xft' '--with-xim'
 '--with-xml2' '--with-xpm' '--with-x-toolkit=gtk2' '--with-x'
 '--x-libraries=/usr/local/lib' '--x-includes=/usr/local/include'
 '--prefix=/usr/local' '--mandir=/usr/local/man'
 '--infodir=/usr/local/share/emacs/info/'
 '--build=i386-portbld-freebsd9.2' 'build_alias=i386-portbld-freebsd9.2'
 'CC=gcc' 'CFLAGS=-O2 -pipe -fno-strict-aliasing' 'LDFLAGS=
 -L/usr/local/lib -Wl,-rpath=/usr/local/lib -ltinfo'
 'CPPFLAGS=-I/usr/local/include' 'CPP=gcpp''

Important settings:
  locale-coding-system: nil
  default enable-multibyte-characters: t

Major mode: Emacs-Lisp

Minor modes in effect:
  display-time-mode: t
  delete-selection-mode: t
  global-whitespace-mode: t
  recentf-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t
  abbrev-mode: t

Recent input:
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo> 
<help-echo> <help-echo> <menu-bar> <file> <Open Recent> 
</home/william/doc/coptic.txt> <help-echo> <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <S-f3> 
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo> 
<help-echo> <help-echo> 1 <help-echo> <help-echo> <help-echo> 
<help-echo> <help-echo> <down-mouse-3> <mouse-3> <down-mouse-3> 
<mouse-3> <help-echo> <help-echo> <help-echo> <help-echo> 
<help-echo> <up> <up> <up> <up> <help-echo> M-z <down> 
<down> <down> C-M-l C-S-l C-S-l C-S-l <right> <down> 
<down> <down> <down> <up> C-S-l C-S-l C-S-l <left> 
<left> <left> <left> <left> s-d <left> s-d <down> <down> 
<down> <down> <up> C-a C-S-l C-S-l C-S-l M-z M-z M-z 
M-z M-z M-z M-z M-z M-z M-1 M-f <help-echo> <help-echo> 
<help-echo> <f1> k <print> <f1> k C-S-x M-1 <help-echo> 
<S-f3> 3 <f3> . e m <tab> . s <tab> <return> <f1> k 
s-d <f1> k C-S-d M-1 <help-echo> <help-echo> <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo> 
<menu-bar> <tools> <compare> <ediff-buffers> <return> 
<return> n n p <switch-frame> n M-z <help-echo> <help-echo> 
<switch-frame> <help-echo> <switch-frame> <switch-frame> 
<help-echo> n <switch-frame> <switch-frame> n <switch-frame> 
<switch-frame> n <switch-frame> <switch-frame> a n 
a n <switch-frame> <switch-frame> a n <switch-frame> 
<switch-frame> a n n n n q <switch-frame> y <switch-frame> 
<f2> M-1 RET M-z <help-echo> M-3 C-S-x r e p <tab> 
o <tab> r <tab> <return>

Recent messages:
Only white-space differences in region 7 
Refining difference region 8 ...
Region 9 in buffer A is empty [2 times]
Region 10 in buffer A is empty [2 times]
Quit this Ediff session? (y or n)  y
Saving file /home/william/.emacs...
Wrote /home/william/.emacs
Undo!
Making completion list... [2 times]
Killing buffer *Completions*

Load-path shadows:
None found.

Features:
(shadow sort gnus-util mail-extr emacsbug message idna format-spec
rfc822 mml mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231
mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums
mm-util mail-prsvr mail-utils time-stamp ediff-merg ediff-diff
ediff-wind ediff-help ediff-util ediff-mult ediff-init ediff
vc-dispatcher vc-rcs ps-print ps-def lpr pp descr-text reposition
edmacro kmacro yasnippet-autoloads package hideshow quail help-mode time
delsel rebox2 cl-macs gv easy-mmode cl rect-mark disp-table whitespace
recentf tree-widget wid-edit easymenu uniquify advice help-fns cl-lib
advice-preload time-date tooltip ediff-hook vc-hooks lisp-float-type
mwheel x-win x-dnd tool-bar dnd fontset image regexp-opt fringe
tabulated-list newcomment lisp-mode register page menu-bar rfn-eshadow
timer select scroll-bar mouse jit-lock font-lock syntax facemenu
font-core frame cham georgian utf-8-lang misc-lang vietnamese tibetan
thai tai-viet lao korean japanese hebrew greek romanian slovak czech
european ethiopic indian cyrillic chinese case-table epa-hook
jka-cmpr-hook help simple abbrev minibuffer loaddefs button faces
cus-face macroexp files text-properties overlay sha1 md5 base64 format
env code-pages mule custom widget hashtable-print-readable backquote
make-network-process dynamic-setting font-render-setting move-toolbar
gtk x-toolkit x multi-tty emacs)

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

[Eli Zaretskii]

> 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.