Path.area() does not work correctly for path1.exclude(path2)

[Pehat]

Description/Steps to reproduce

var path1 = new paper.Path([
    [100, 100],
    [200, 100],
    [200, 200],
    [100, 200]
]);
path1.closed = true;
path1.strokeColor = "red";
path1.visible = true;

var path2 = new paper.Path([
    [190, 190],
    [290, 190],
    [290, 290],
    [190, 290]
]);
path2.closed = true;
path2.strokeColor = "blue";
path2.visible = true;

var xor_path = path1.exclude(path2);
xor_path.strokeColor = null;
xor_path.fillColor = "lime";
xor_path.visible = true;
console.log(path1.area);  // expected 10000
console.log(path2.area);  // expected 10000
console.log(xor_path.area);  // expected 19900, got eps
console.log(xor_path.children[0].area);  // expected 9900
console.log(xor_path.children[1].area);  // expected 9900, got -9900

Link to reproduction test-case

Sketch link

Expected result

The intersection of two Path objects should have the area rendered in green. In fact, looks like it simply sums the oriented areas of underlying paths, regardless are they really rendered or not.