Variable font rendering: Diacritics based on composites are misaligned to base glyph

[herrstrietzel]

Apparently, Opentype.js 2.0 has issues rendering glyphs with diacritics correctly in VFs

Steps to reproduce

Set variation setting deviating from the fonts defaults like so

font.variation.set({ wght: 200, wdth: 75 });

Diacritic/component alignment works correctly for default axes like

font.variation.set({ wght: 400, wdth: 400});

When inspecting the glyph's components the dx values stick to the default values (wght:400, wdth:100) regardless of the current axes settings.

Assumption this issue may be caused by a miscalculation in function buildPath(glyphs, glyph) missing dx adjustments.

Tested with these VF fonts:

• Roboto Flex', "https://fonts.gstatic.com/s/robotoflex/v26/NaPccZLOBv5T3oB7Cb4i0wu9TsDOCZRS.ttf"
• 'Open Sans', "https://fonts.gstatic.com/s/opensans/v40/mem8YaGs126MiZpBA-U1UpcaXcl0Aw.ttf"
• Noto Sans', "https://fonts.gstatic.com/s/notosans/v37/o-0IIpQlx3QUlC5A4PNb4j5Ba_2c7A.ttf"

Reproducible in the font inspector demo
using https://opentype.js.org/dist/opentype.js;

See also codepen