Crash when loading STHeiti Medium.ttc

[fishkingsin]

Hei.ttf is ok
Arial Unicode.ttf is also ok
but
when draw "STHeiti Medium.ttc" from mac system font
it crash

const FTGlyph* const FTGlyphContainer::Glyph(const unsigned int charCode) const
{
unsigned int index = charMap->GlyphListIndex(charCode);
return glyphs[index]; <-------------------
}