Dear Kazuki Maeda, Thank you very much for your bug report and patch. I've reported it on luaotfload tracker: https://github.com/lualatex/luaotfload/issues/289 and will ask Hans about it (he's the author of the upstream ConTeXt code). Is one of these fonts publicly available? If not, could you send it to me privately?
Best Regards, -- Elie
