I am developing a font with ligatures and small caps. I have the Liga and Smcp features working nicely by themselves. But while testing, if I convert a word that contains a ligature to small caps, the ligature remains and the rest of the glyphs are converted.

How do I tell the Smcp feature to convert the ligatures back to their original glyphs and then to small caps?

I could turn the ligature feature off in my design app before I convert to small caps but I would rather see this work automatically. I've see fonts that do this but I am lost trying to figure it out.