Commas in strange location when using Latin text

[David D Lowe]

If you open LibreOffice in Ubuntu 18.04 and type some English text using the Scheherazade font that comes with fonts-sil-scheherazade , you experience this issue. The commas are rendered in the wrong position, they are rendered too high up. Also, the spacing after the comma is missing. See the attached screenshot.

[David D Lowe (flimm)]

I first discovered this issue when rendering text in the Scheherazade font in Firefox. See this bug report: https://bugzilla.mozilla.org/show_bug.cgi?id=1614575

They said:

> Ah, I see ... it appears this is a bug in the font, but only in its Graphite layout behavior. If you set gfx.font_rendering.graphite.enabled to false in about:config, the problem disappears, as we then use the OpenType layout tables. Chrome doesn't support Graphite rendering, so the problem doesn't show up there.

> And the problem doesn't occur when using the font served by Google Fonts (rather than a locally-installed copy) because Google serves a copy of the font where the Graphite tables have been removed.

> Further confirmation: I see the same bad result if I use the font in LibreOffice (which does support Graphite).

> So this is not a Firefox bug, it's a font bug; I'll let the SIL team responsible for Scheherazade know about it. Meanwhile, as a workaround you can disable Graphite in Firefox as mentioned above.

This confirms that the problem is in the Scheherazade font file shipped with Ubuntu in the package fonts-sil-scheherazade.