In Feisty, with non-Chinese locale (e.g. en_US.UTF-8), if set default system font to an English font (Sans serif, Bitstream Vera San, etc.) in kcontrol/qtconfig, QT programs neglect all the Chinese fonts in Fontconfig's "alias" list or QT's own font substitution list. Chinese characters are displayed ugly with possibly a Japanese font.
GTK+ program will conform the settings in fontconfig and correctly display all the Chinese characters with proper font.
If locale is set to zh_CN.UTF-8, Chinese font then get the highest priority in QT apps, even the font Sans serif are displayed using the Chinese font.
Binary package hint: libqt3-mt
In Feisty, with non-Chinese locale (e.g. en_US.UTF-8), if set default system font to an English font (Sans serif, Bitstream Vera San, etc.) in kcontrol/qtconfig, QT programs neglect all the Chinese fonts in Fontconfig's "alias" list or QT's own font substitution list. Chinese characters are displayed ugly with possibly a Japanese font.
GTK+ program will conform the settings in fontconfig and correctly display all the Chinese characters with proper font.
If locale is set to zh_CN.UTF-8, Chinese font then get the highest priority in QT apps, even the font Sans serif are displayed using the Chinese font.
libqt3-mt version: 3:3.3.8-0ubuntu2 (feisty)