Invalid difference for multipolygon with touching polygons enclosing exterior

[awulkiew]

If such multipolygon is subtracted the result is a polygon with touching holes enclosing interior. Such polygon is invalid: "Geometry has disconnected interior". The result should be two polygons, one with a hole and second one inside this hole.

Tested with VS2022 (msvc-14.3), Boost.Geometry develop (1.83-beta1).

Examples:

---

A = "POLYGON((-1 -1,-1 9,9 9,9 -1,-1 -1))";
B = "MULTIPOLYGON(((0 1,0 2,1 2,1 1,0 1)),"
                 "((5 0,1 0,1 1,4 1,4 2,1 2,1 3,5 3,5 0)))";

The result of A\B is

"MULTIPOLYGON(((-1 -1,-1 9,9 9,9 -1,-1 -1),(0 1,1 1,1 2,0 2,0 1),(5 0,5 3,1 3,1 2,4 2,4 1,1 1,1 0,5 0)))"

---

A = "POLYGON((-1 -1,-1 9,9 9,9 -1,-1 -1))";
B = "MULTIPOLYGON(((0 1,0 2,1 2,1 1,0 1)),"
                 "((1 2,1 3,2 3,2 2,1 2)),"
                 "((2 1, 2 2, 3 2, 3 1, 2 1)),"
                 "((1 0, 1 1, 2 1, 2 0, 1 0)))";

The result of A\B is

"MULTIPOLYGON(((-1 -1,-1 9,9 9,9 -1,-1 -1),(0 1,1 1,1 2,0 2,0 1),(1 2,2 2,2 3,1 3,1 2),(2 1,3 1,3 2,2 2,2 1),(1 0,2 0,2 1,1 1,1 0)))"