Added test for polygon with hole

testdata/scad/features/polygon-tests.scad

@@ -15,4 +15,10 @@ translate([-2,0,0]) polygon(points);
 translate([-2,-2,0]) polygon(points=points, paths=[[0,1,2,3], [4,5,6,7]]);
 translate([2,-4,0]) polygon([[0,0], [1,0], [1,1], [0,0]]);
 
+// With hole
+translate([-2,-4,0])
+  polygon(points=[[0,0], [1,0], [1,1], [0,1], [0.2,0.2], [0.8,0.2], [0.8,0.8], [0.2,0.8]],
+          paths=[[0,1,2,3],[4,5,6,7]]
+);
+
 // FIXME: convexity

tests/regression/dumptest/polygon-tests-expected.csg

@@ -33,4 +33,7 @@ group() {
 	multmatrix([[1, 0, 0, 2], [0, 1, 0, -4], [0, 0, 1, 0], [0, 0, 0, 1]]) {
 		polygon(points = [[0, 0], [1, 0], [1, 1], [0, 0]], paths = undef, convexity = 1);
 	}
+	multmatrix([[1, 0, 0, -2], [0, 1, 0, -4], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+		polygon(points = [[0, 0], [1, 0], [1, 1], [0, 1], [0.2, 0.2], [0.8, 0.2], [0.8, 0.8], [0.2, 0.8]], paths = [[0, 1, 2, 3], [4, 5, 6, 7]], convexity = 1);
+	}
 }