U+0600 U+0601 U+0602 U+0603 overlap the preceding letters in NotoNaskhArabic and NotoNaskhArabicUI

[nizarsq]

In NotoNaskhArabic and NotoNaskhArabicUI U+0600 U+0601 U+0602 U+0603 overlap the preceding letters. Look like there is zero width for those codepoints

Issue found in:


NotoNaskhArabic Version 2.000
https://github.com/googlefonts/noto-fonts/tree/master/unhinted/ttf/NotoNaskhArabic/NotoNaskhArabic-Regular.ttf
NotoNaskhArabicUI Version 2.000
https://github.com/googlefonts/noto-fonts/tree/master/unhinted/ttf/NotoNaskhArabicUI/NotoNaskhArabicUI-Regular.ttf

Characters data used in the test:
في ؀ في في ؁ في في ؂ في في ؃ في

Screenshot:

[nizarsq]

This issue still need work NotoNaskhArabic and NotoNaskhArabicUI

[nizarsq]

@marekjez86 for opinion

[khaledhosny]

The symbols seem to have negative right side bearing on the assumption that are always used in combination of digits. This is probably wrong, and they should be given positive side bearings and combine only with digits using GPOS positioning. Doing the later is trickey though, since HarfBuzz and non-HarfBuzz engines behave differently;y due to a long standing HarfBuzz issue: harfbuzz/harfbuzz#501

[marekjez86]

@nizarsq : I think we should wait until harfbuzz is fixed, but I don't know what's worse: (1) negative right side bearing [as it is right now] or (2) change it to positive side bearings [but don't handle GPOS positioning until harfbuzz is fixed] ... I'm leaning toward not-doing anything until some later date

[simoncozens]

This is kind of a duplicate of #34.