[ft-devel] Variable fonts: hhea/typo/win metrics interpreted differently for instances compared to static fonts?

[Nikolaus Waxweiler]

Hi list,
I'm trying to turn Cantarell into a VF and am hitting a hhea/typo/win 
metrics issue: the metrics seem to be interpreted differently for the 
VF instances compared to the static fonts an I'm not sure if I'm doing 
something wrong. The instances look as if their baseline was shifted 
upwards relative to the static fonts. Equalizing hhea and typo metrics 
makes the difference go away.

Here's a screenshot of the baseline difference: 
https://github.com/googlei18n/fontmake/issues/492#issuecomment-447760311

Here are the three static masters and the resulting VF: 
https://github.com/googlei18n/fontmake/issues/492#issuecomment-448005088

(Note that the Regular serves as the master for various fields, e.g. 
the "Use Typo Metrics" bit. Toggling it does not help.)

This happens on master and on 2.9.1. Am I overlooking something?