FreeSerif ligatures not working in Musescore
Mac OS 10.13.6
Musescore 188.8.131.5242, revision 58dd23d
Ligatures not appear to be working with FreeSerif. I have tested this font in other programs (screenshot attached of words with f-ligatures set in Adobe Illustrator), and there does not appear to be anything wrong with the font itself.
Ligatures appear to work with other fonts in Musescore — I tried Adobe Garamond and a handful of others — and the letter combinations of fi, fl, ffi, ffl and ff were all properly substituted with ligatures.
To test the fonts themselves, I re-compiled the feature set of the four FreeSerif fonts in FontLab VI (Version 184.108.40.20616), and exported the fonts in the same format (OpenType TT), replaced the fonts in the Musescore resources/font folder with the new versions, and restarted my Mac. But the issue persists.
It is possible that FreeSerif has become too robust — it supports many languages, including Cherokee, Georgian and Thai — and that certain code is simply ignored by MuseScore because there is no room in memory to process it. I bring up this possibility because of an issue I used to have with Microsoft Word. If you used a font that had over 500 kerning pairs, it simply ignored all of the kerning in the font. Maybe something like this is happening with Musescore. I've also attached a file that uses the word "Affettuoso" set in FreeSerif Bold Italic, and a screen shot of the problem as well.
Perhaps there is a section of memory defined in Musescore for individual fonts that needs to be enlarged for the OT features to take effect, especially since there is so much code in this font it might simply be running out of space.