Ligatures should not be added to Arabic positional features

Glyphs
#1

I don’t know if this is an old or new behavior, but I just noticed that autogenerated fina feature has entries for ligatures, e.g.:

sub lam_alef-ar by lam_alef-ar.fina;

Although this is harmless, but also redundant since positional features are applied before ligature features.

#2

That is portably like that for some time.

#3

Possibly. I don’t usually have any ligatures so I wouldn’t have noticed it, but this is ligature-heavy project and I have tens of these redundant substitutions.