Here I am attaching a test suite for the conf files submitted in this bug.
I hope everyone who want to help with this bug to do the following:

1. follow the README.txt and see if you can reproduce what I got
   in this album:
   http://picasaweb.google.com/fangqq/Fontconfig_65nonlatin_test#

2. if you want to help to improve or revise these files, please do it
   with regression tests as outlined in the README.txt and make sure it
   does not break anything that is already working

3. justify each change you made to 65-nonlatin, 41-language-zh and
    41-language-ja files (patches are more welcome than theoretical 
criticism)

 From my tests, I see all CJK fonts rendered consistently under
all en/zh/ja locales.


Here is a copy of the README.txt file:


==  1. What is in this package  ==

The attached conf.d folder contains the conf.d folder
in the latest fontconfig 2.8.0 release with the following
modifications:

  1. the 65-nonlatin.conf was updated by attachment
     http://bugs.freedesktop.org/attachment.cgi?id=27952
     (2009-07-23 08:01 PST, MATSUU Takuto)
  2. two new files:
       41-language-zh.conf from attachment
       http://bugs.freedesktop.org/attachment.cgi?id=27955
       (2009-07-23 10:16 PST, Qianqian Fang)
     and
       41-language-ja.conf from attachment
       http://bugs.freedesktop.org/attachment.cgi?id=27951
       (2009-07-23 07:52 PST, MATSUU Takuto)

nothing else is touched.


==  2. How to test  ==

2.1 Install the necessary CJK fonts

For debian/ubuntu (>=9.10):
   apt-get install ttf-wqy-zenhei ttf-wqy-microhei xfonts-wqy \
    ttf-arphic-uming ttf-arphic-ukai ttf-vlgothic ttf-unfonts

For fedora/redhat (>=F11):
   install wqy-bitmap-fonts wqy-zenhei-fonts cjkuni-uming-fonts
           cjkuni-ukai-fonts vlgothic-fonts vlgothic-p-fonts
           sazanami-mincho-fonts sazanami-gothic-fonts ipa-gothic-fonts
           ipa-mincho-fonts ipa-pgothic-fonts ipa-pmincho-fonts
           and also some version of un-fonts


For Fedora, if you want to install wqy-microhei, you can
download it from
http://sourceforge.net/projects/wqy/files/wqy-microhei/0.2.0-beta/

extract it and put the wqy-microhei.ttc to ~/.fonts folder.


2.2 Set up the new conf.d folder

You need to temporarily replace the current conf.d folder
by what's included in this package. Something like this

sudo mv /etc/fonts/conf.d /etc/fonts/conf.old
sudo mv /path/to/this/folder/conf.d /etc/fonts/conf.d
sudo mv ~/.fonts.conf ~/.fonts.conf_old
sudo fc-cache -fv

Please install the fonts first before you
switch the folder; otherwise, some font installation
may alter or add new files to the conf.d directory.


2.3 Run the test

The goal of the test is to show
1. whether the CJK rules have any side-effect to non-CJK locales
2. whether users can read consistent CJK text rendering under non-CJK 
locales
3. whether users can read consistent CJK text under the respective CJK 
locales

To do this, you need to fill the following matrix:

    bitmap status         webpage language   desktop language/locale
----------------------------------------------------------------------
 {no_bitmap,with_bitmap} - {en,zh,ja_page} - {en_US, zh_CN, ja_JP}

In another word, you need to logon your account with en/zh/ja language
as your desktop language, and then browse an English-only page,
a simplified Chinese page, a Japanese page in your browser.

"no_bitmap" means vector-priority settings. This means
you need to remove "wqy bitmap song" from the list.
For testing purposes, this can be done by moving the font files
(locate wenquanyi_ | grep .pcf ) to /tmp/

You should also pay attention to the monospaced font used in
your terminal software, and also the desktop toolbars and menus.


The suggested test pages include:

Chinese : http://wenq.org/?WQYTest
Japanese: http://news.google.com/news?ned=jp
English 
:http://www.google.com/support/news/bin/answer.py?answer=40237&topic=8851&hl=en



==  3. What should you expect  ==

1. English (non-CJK) page fonts will not be effected at all
2. In non-CJK locales, when viewing CJK pages, simplified Chinese
   fonts will be used to render all the text
3. In ja_JP locale, Japanese fonts will be used for all text rendering
4. In zh_CN locale, Chinese fonts will be used for all text rendering


==  4. Clean up script after the test ==

sudo mv /etc/fonts/conf.d /etc/fonts/conf.new
sudo mv /etc/fonts/conf.old /etc/fonts/conf.d
sudo mv ~/.fonts.conf_old ~/.fonts.conf
sudo fc-cache -fv


if everything look ok, then you can delete
folder /etc/fonts/conf.new