Gates must be one block taller than gates.minHeight #2110

With the default gates.minHeight: 3 (and the user guide's "Must be at least 3 blocks high"), a gate made of a 3-block-tall column is refused with "Gates must be at least 3 blocks tall." A 4-block column is accepted.

Cause: MfCuboidArea.height is maxPosition.y - minPosition.y, the gap between the top and bottom rows, so a three-block column has a height of 2. The check in PlayerInteractListener compares that with minHeight directly.

Evidence: behaviour-gate bot rig, Spigot 1.21.1, MF 7.0.0 and dev: creating a 1×3 oak-plank gate fails with that message, and a 1×4 gate is created.

drafted by Claude on behalf of Daniel Stephenson