I notice that the current version (including the latest stable 3260) fails to export Arabic font with cursive attachment + kerning. The “kerning” is achieved by sneaking elevation-checker glyphs (set as non-spacing marks), and implemented in a couple of retails fonts I’ve done.
The latest Glyphs seems to handle mark feature differently, and prevent letters from connecting when the mark glyphs are present. How can I fix this?
Their custom glyph info are Arabic, Mark, Nonspacing (maybe I should add RTL? it makes no difference though).
The curs code looks fine, nothing jumps out as odd.