tree a9ae380eb1050bd16a121046425e447558a67643
parent 8f88131a78a8736a34ddb24a3e38bda92696b835
author ReadRoberts <rroberts@adobe.com> 1560375030 -0700
committer ReadRoberts <rroberts@adobe.com> 1560375030 -0700

[varLib.merger]  Fix merging GPOS SinglePos subtables

When a SinglePost lookup is compiled, pretty much all compilers do some compression by combining similar ValueRecords into a single subtable. This compression produces different lengths of the list of subtables between source fonts. The original code required that all SinglePos lookups have the same subtables, often doesn't work.

I fixed this in varLib.merger.py by first flattening a SinglePos lookup to a single subtable, using the same record format for all records, and then merging the source fonts. After the merge is complete, I call fontTools.otlLib.builder.buildSinglePos() to rebuild the lookup subtables.