Robustness failure in VoronoiDiagramBuilder

[dbaston]

The following geometry (a 7-point MultiPoint) causes VoronoiDiagramBuilder to throw an exception, even with a very large tolerance value relative to the scale of the input points (such as 0.1).

01040000000700000001010000000f8b33e3d97742c038c453588d0423c001010000001171d6d1b45d42c06adc1693e78c22c001010000001c8b33e3d97742c062c453588d0423c00101000000afa5c71fda7742c04b93c61d8e0423c00101000000b0cddcb4b57942c026476887d7b122c00101000000e0678421dc7642c0f7736021e1fb22c00101000000e32fd565018d42c0c7ea1222167c22c0

Originally reported in PostGIS at https://trac.osgeo.org/postgis/ticket/3447

[dr-jts]

The error thrown is:

Invalid number of points in LinearRing (found 2 - must be 0 or >= 4)

The actual cause is that the Delaunay triangulation is not computed correctly for some reason (it has crossing edges).