public void TestSimplifyBadPoly() { var geom = new WKTReader().Read("POLYGON ((1 1, 1 1, 1 1, 1 1, 1 1))"); var geom2 = new Polygon(new LinearRing(new Coordinate[] { new Coordinate(1, 1), new Coordinate(1, 1), new Coordinate(1, 1), new Coordinate(1, 1), new Coordinate(1, 1) })); Debug.WriteLine("Bad polygon: " + geom); var simple = DouglasPeuckerSimplifier.Simplify(geom, 0.1); Debug.WriteLine("Simple bad polygon: " + simple); Assert.AreEqual(geom.GetType(), simple.GetType()); Assert.AreNotEqual(geom, simple, "Simplify didn't do anything to this invalid polygon."); // This happens with JTS 1.9.0, 1.8.0 still returns GeometryCollection.Empty Assert.AreEqual(geom.GetType(), Polygon.Empty); }