> > I have found that FT_Get_Char_Index will explicitly return 0 for 'missing' > characters which is the fix for the issue. I am using FT_Load_Char but should > that really return a valid construct for an "invalid" character? >
This is ridiculous. You are complaining about very basic typographic concepts.I welcome you to educate yourself: https://docs.microsoft.com/en-us/typography/opentype/spec/recom#glyph-0-the-notdef-glyph
