[Fontconfig] How to match on charset?

[Robert Siemer]

Hello everyone!

I tracked the chromium-browser down to do ask for fonts with a specific 
character. E.g.:

FcConfigSubstitute Pattern has 2 elts (size 16)
         scalable: FcTrue(s)
         charset:
         0066: 00000000 00008000 00000000 00000000 00000000 [...]

[U+662F is a Chinese character I entered in a form.]


Now I want to catch that request via configuration and return a specific 
font like here:

     <match target="pattern">
         <test name="lang" compare="contains">
             <string>zh</string>
         </test>
         <edit name="family" mode="prepend">
             <string>AR PL KaitiM GB</string>
         </edit>
     </match>


But how do I match a request for a character (range)??
Playing around with fc-match resulted in segmentation faults...


Any insights?


Thanks,
Robert


PD: In the example I search lang for a containing “xx” instead of “zh” 
in reality because of a peculiarity in fontconfig...