Bug#620004: libpango1.0-0: Weird cursor movements on Thai leading/following vowels

[Theppitak Karoonboonyanan]

Package: libpango1.0-0
Version: 1.28.3-5
Severity: normal
Tags: patch

As reported upstream since Pango 1.23.x in GNOME #576156, cursor movement
on Thai leading/following vowels introduced in that version has been
counter-intuitive to Thai users. Instead of moving cell by cell, it skips
leading and following vowels, causing unexpected editing behavior.

  https://bugzilla.gnome.org/show_bug.cgi?id=576156

This bug has also caused failed tests on Mozilla:

  https://bugzilla.mozilla.org/show_bug.cgi?id=474068

The same problem has been fixed elsewhere, including Chromium browser
and ICU, but not Pango. Instead, upstream insists on conformance to
Unicode Annex #29, no matter how it's against all practical uses on earth,
such as evidences shown in Mozilla bug:

  https://bugzilla.mozilla.org/show_bug.cgi?id=474068#c65

UAX#29 amendments have been proposed for many times, but got rejected.
The last hope is that my recent evidences could convince the committee.
It's under progress, BTW.

Meanwhile, I have maintained my patched package in a local repository
for Thai users, with rebuilding on every sid update for the past 2 years,
as also mentioned in Bug #620001 and #620002:

  http://ftp.debianclub.org/debclub/pool/main/p/pango1.0/

It should be good to get the patch included in sid, to get the downstream
difference reduced, until the necessary action is taken upstream (both
Unicode and GNOME).

Regards,
-- 
Theppitak Karoonboonyanan
http://linux.thai.net/~thep/

-- System Information:
Debian Release: wheezy/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 2.6.38-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=th_TH.UTF-8, LC_CTYPE=th_TH.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages libpango1.0-0 depends on:
ii  fontconfig                    2.8.0-2.1  generic font configuration library
ii  libc6                         2.11.2-13  Embedded GNU C Library: Shared lib
ii  libcairo2                     1.10.2-6   The Cairo 2D vector graphics libra
ii  libfontconfig1                2.8.0-2.1  generic font configuration library
ii  libfreetype6                  2.4.4-1    FreeType 2 font engine, shared lib
ii  libglib2.0-0                  2.28.2-1   The GLib library of C routines
ii  libthai0                      0.1.15-1   Thai language support library
ii  libx11-6                      2:1.4.2-1  X11 client-side library
ii  libxft2                       2.2.0-2    FreeType-based font drawing librar
ii  libxrender1                   1:0.9.6-1  X Rendering Extension client libra

Versions of packages libpango1.0-0 recommends:
ii  x-ttcidfont-conf              32         TrueType and CID fonts configurati

Versions of packages libpango1.0-0 suggests:
pn  ttf-arphic-bkai00mp           <none>     (no description available)
pn  ttf-arphic-bsmi00lp           <none>     (no description available)
pn  ttf-arphic-gbsn00lp           <none>     (no description available)
pn  ttf-arphic-gkai00mp           <none>     (no description available)
ii  ttf-baekmuk                   2.2-3      Baekmuk series TrueType fonts
ii  ttf-sazanami-gothic [ttf-japa 20040629-8 Sazanami Gothic Japanese TrueType 
ii  ttf-sazanami-mincho [ttf-japa 20040629-8 Sazanami Mincho Japanese TrueType 
pn  ttf-thryomanes                <none>     (no description available)

-- no debconf information