/clone overlapping detected in odd ways

The game compares two cuboids from the given coordinates to judge the overlap. However, the two cuboids do not frame the entire selection area for cloning.

for example：
/clone 0 5 0 1 6 1 1 6 0

As expected, the source area is a cube with 2 meters of side length. And the source area overlaps with the target area. But the game will not judge they overlap.

After many tests, I think that the game judges overlap as shown in images.

Other examples：
/clone ~ ~ ~ ~ ~ ~ ~ ~ ~
/clone 0 5 0 2 7 2 2 7 0