Bug: Incorrect triangulation

[gkjohnson]

Hello! I'm using three.js' earcut function (which uses code from this project) and I'm seeing incorrect triangulation on (admittedly complex) cases. Here the black outline represents the shape being triangulated and the pink is the triangulated volume:

I'm not seeing the issue when disabling holes so this could be a duplicate of #162:

If needed I can export the shape and produce a minimal repro using this earcut code rather than three.js'. And if there are any known trouble cases it would be good to know them. I've seen that cases where line segments intersect, for example, can cause incorrect triangulation - but I've verified that this shape does not have such cases.

Thank you for the great project!