Comment 42 for bug 521163

sorry, Once again, I want not to add WenQuanYi Micro Hei, WenQUanYi Zen Hei, and Droid Sans Fallback before japanese fonts.

Even in japanese locale, they are appeared as sans-serif fonts because they have 'ja' in lang attribute.

$ LANG=ja_JP.UTF-8 fc-match sans-serif
wqy-microhei.ttc: "WenQuanYi Micro Hei" "Regular"

$ fc-match -v 'WenQuanYi Micro Hei' | grep 'family\|lang'
        family: "WenQuanYi Micro Hei"(s)
        familylang: "zh-tw"(s)
        stylelang: "en"(s)
        fullnamelang: "en"(s)
        lang: aa|ab|af|ast|ava|ay|ba|be|bg|bi|bin|br|bs|bua|ca|ce|ch|chm|co|cs|cu|cv|cy|da|de|el|en|eo|es|et|eu|fi|fj|fo|fr|fur|fy|gd|gl|gn|gv|ho|hr|hu|ia|ibo|id|ie|ik|io|is|it|ja|kaa|ki|kk|kl|ko|ku|kum|kv|ky|la|lb|lez|lt|lv|mg|mh|mk|mt|nb|nds|nl|nn|no|nr|nso|ny|oc|om|os|pl|pt|rm|ru|sah|se|sel|sh|sk|sl|sma|smj|smn|so|sq|sr|ss|st|sv|sw|tg|tk|tn|tr|ts|tt|tyv|uk|uz|vo|vot|wa|wen|wo|xh|yap|zh-cn|zh-sg|zh-tw|zu(s)

$ fc-match -v 'WenQuanYi Zen Hei' | grep 'family\|lang'
        family: "WenQuanYi Zen Hei"(s)
        familylang: "zh-tw"(s)
        stylelang: "zh-tw"(s)
        fullnamelang: "zh-tw"(s)
        lang: aa|af|ast|ava|ay|be|bg|bi|br|ca|ce|ch|co|da|de|el|en|es|eu|fj|fo|fr|fur|fy|gd|gl|gv|ho|ia|id|ie|ik|io|is|it|ja|ko|kum|lb|lez|mg|nb|nds|nl|nn|no|nr|ny|oc|om|os|pt|rm|ru|sel|sh|sm|sma|smj|so|sq|sr|ss|st|sv|sw|to|ts|vo|wa|wo|xh|yap|zh-cn|zh-hk|zh-mo|zh-sg|zh-tw|zu(s)

$ fc-match -v 'Droid Sans Fallback' | grep 'family\|lang'
        family: "Droid Sans Fallback"(s)
        familylang: "en"(s)
        stylelang: "en"(s)
        fullnamelang: "en"(s)
        lang: bg|fj|ho|ia|ie|io|ja|ko|kum|nr|om|os|ru|sel|so|ss|st|sw|ts|xh|zh-cn|zh-sg|zh-tw|zu(s)

FYI, all japanese fonts doesn't have zh and ko in lang.

$ fc-match -v 'IPAPGothic' | grep 'family\|lang'
        family: "IPAPGothic"(s)
        familylang: "en"(s)
        stylelang: "en"(s)
        fullnamelang: "en"(s)
        lang: aa|ast|ay|bg|bi|br|ch|cs|da|de|en|eo|es|et|eu|fi|fj|fo|fur|fy|gd|gl|gv|ho|hu|ia|id|ie|io|is|it|ja|kum|lb|mg|nb|nds|nl|nn|no|nr|nso|oc|om|os|pl|pt|rm|ru|sel|sk|sma|smj|so|sq|ss|st|sv|sw|tn|ts|vo|vot|wa|wen|xh|yap|zu(s)

I think these chinese fonts should drop ja and ko in lang attribute.
or could fontconfig drop ja and ko from lang attribute?