harfbuzz/test/api/fonts
..
Inconsolata-Regular.ab.ttf
Inconsolata-Regular.abc.ttf
Inconsolata-Regular.abc.widerc.ttf
Inconsolata-Regular.ac.ttf
Inconsolata-Regular.ac.widerc.ttf
MathTestFontEmpty.otf
MathTestFontFull.otf
MathTestFontNone.otf
MathTestFontPartial1.otf
MathTestFontPartial2.otf
MathTestFontPartial3.otf
MathTestFontPartial4.otf
Mplus1p-Regular.660E,6975,73E0,5EA6,8F38,6E05.ttf
Mplus1p-Regular.660E.ttf
README
Roboto-Regular.D7,D8,D9,DA,DE.ttf
Roboto-Regular.abc.cmap-format12-only.ttf
Roboto-Regular.abc.format4.ttf
Roboto-Regular.abc.format12.ttf
Roboto-Regular.abc.ttf
Roboto-Regular.ac.cmap-format12-only.ttf
Roboto-Regular.ac.nohints.ttf
Roboto-Regular.ac.ttf
Roboto-Regular.b.ttf
Roboto-Regular.components.1fc.nohints.ttf
Roboto-Regular.components.subset.ttf
Roboto-Regular.components.ttf
Roboto-Regular.gsub.fi.ttf
Roboto-Regular.gsub.fil.ttf
Roboto-Regular.multihdmx.a.ttf
Roboto-Regular.multihdmx.abc.ttf
Roboto-Regular.nogsub.fi.ttf
cv01.otf

README

cmap-format12-only files created by ttx & remove all other cmap entries

Inconsolata-Regular.abc.widerc.ttf has the hmtx width of "c" set to 600; everything else is 500. Subsetting out c should reduce numberOfHMetrics to 1.