re: a horrible thought
a quick survey of the fonts on my debian install reveals:
- Default 'sans serif', 'serif', and 'monospace' fonts: correct!
- DejaVu: mostly correct, although DejaVu Sans (non fallback) is a fail as it doesn't render any mark above the J.
- Hack, Liberation: fail, two marks on the J
- Nimbus: fail, two marks on the J, and it's trying to escape to the left
- Noto: mostly correct, although Cherokee, CJK, Coptic, Georgian, and Math variants fail by rendering two marks
- OpenSymbol: fail. renders the acute as if it were its own letter
- Quicksand, Symbola, URW Bookman and URW Gothic: fail, two marks on the J
all in all, a decent showing? from the default fonts especially.