Broken SVG table for Aref Ruqaa Ink fonts downloaded from the website

[khaledhosny]

The fonts downloaded from https://fonts.google.com/specimen/Aref+Ruqaa+Ink have broken SVG table with glyph IDs not matching between SVG table and the rest of the font. The files from https://github.com/google/fonts/tree/main/ofl/arefruqaaink seem to be fine.

[khaledhosny]

See https://gitlab.freedesktop.org/freetype/freetype-demos/-/issues/30

[RosaWagner]

Maybe @anthrotype or @rsheeter want to take a look at this issue?

[anthrotype]

thanks for filing this, yeah the GID look all messed up. Interestingly the SVG table from the fonts inside the ZIP is identical to the one on Github https://github.com/google/fonts/tree/main/ofl/arefruqaaink, the rest of the font (especially the GlyphOrder) is different though (even though they both claim to be the same fontRevision=1.005). The number of glyphs is different, 1184 (downloaded font) vs 1192 (Github copy). Also the cmap is the same... 🤔 💭
Maybe the downloaded font has gone through some subsetting operation that left the SVG table intact but didn't keep the old glyph IDs. FontTools subsetter can subset the SVG table but hb-subset cannot. In theory I would expect that if we do use hb-subset at all on SVG fonts we at least retain the glyph IDs. I will keep investigating.

[anthrotype]

ok yes, I was able to reproduce using hb-subset command line tool.
If you take the original unsubsetted font from Github at https://github.com/google/fonts/tree/main/ofl/arefruqaaink, and pass it through hb-subset without passing the --retain-gids option, the glyph indices are going to be messed up exactly in the same way as the font from the download zip.
There seems to be 8 glyphs that are unreachable when subsetting with --unicodes='*' so hb-subset drops them (which explains the the difference in the number of glyphs between the two fonts 1192 - 8 = 1184).

# with --retain-gids the font works
$ hb-subset --retain-gids --drop-tables-=SVG --passthrough-tables --output-file=ArefRuqaaInk-Regular-GH.hb-subset.ttf --unicodes='*' ArefRuqaaInk-Regular-GH.ttf
# without --retain-gids the indices are messed up because 8 unreferenced glyphs get dropped but SVG table is kept as is
$ hb-subset --drop-tables-=SVG --passthrough-tables --output-file=ArefRuqaaInk-Regular-GH.hb-subset-no-retain-gids.ttf --unicodes='*' ArefRuqaaInk-Regular-GH.ttf

[anthrotype]

I filed an issue internally (b/284117255)

[garretrieger]

A fix for this should be coming early next week.

[HinTak]

I reckon you'll regenerated all the zip files involving fonts with SVG tables, but FWIW, another font, Blaka Ink Regular, is also broken. (I was the one who played with all the non-sans Google arabic fonts recently, and draw Werner's attention to Aref Ruqaa at the beginning).

[garretrieger]

Yes that's right. The plan is to update all families which have SVG tables. That should be happening tomorrow or Wednesday.

[garretrieger]

This should be fixed now.

[anthrotype]

Thanks!