Overlapping Syriac glyphs

[dscorbett]

Font

NotoSansSyriac-Regular.ttf

Where the font came from, and when

Site: https://github.com/googlefonts/noto-fonts/blob/af306de71ce51b9ce75389b163026427953606cf/phaseIII_only/unhinted/ttf/NotoSansSyriac/NotoSansSyriac-Regular.ttf
Date: 2019-04-26

Font version

Version 2.000

Issue

In the Estrangelo and Western Syriac styles of this font, glyphs with negative side bearings may overlap.

Character data

ܨܢ
U+0728 SYRIAC LETTER SADHE
U+0722 SYRIAC LETTER NUN

Screenshot

'SYR ' or 'SYRE':

'SYRJ':

[r12a]

Isn't this supposed to happen? For example, see the result with the following fonts:

Serto Jerusalem (Western)

Estrangelo Edessa

Estrangelo Antioch

(Eastern fonts like Adiabene and Ctesiphon don't create this ligated form. There are other letter combinations that produce ligated forms only in certain styles.)

[dscorbett]

Does it matter whether the nun crosses through the sadhe? In Noto it doesn’t but in those other fonts it does.