Bukkit

v2.3:

• Updates knocking: it will now open the portcullis but close it right after opening. This lets you pass through the gate, but by closing it, it restores it to the previous state, and so is in sync with whatever activator block controls it. This is especially useful if you have set it up to be controlled by a daylight sensor, for example. Also player in creative mode can now knock on the portcullis.
• Fixes a ConcurrentModificationException if you broke the last top block in a portcullis. It did not cause any observable bug, but it did spam the console.