[1.1.6] Spidertron leg collision boxes cannot be turned off

[Xorimuth]

To reproduce, set the spidertron leg collision boxes to `nil` at https://github.com/wube/factorio-data/b ... es.lua#L84.

They disappear from the `show-collision-rectangles` debug view but you can still crash into the legs with eg a car.

[Rseding91]

Thanks for the report however this isn't related to the spidertron legs; the logic is in cars and that they will collide with things that have zero sized bounding boxes if the collision mask collides with the cars collision mask (as intended).

You need to make the two collision masks not collide if you want them to not collide.

[Xorimuth]

Thanks very much. Setting the legs' collision masks to `{}` fixed the problem.