Copy rails

The piston will create a list of blocks that will be pushed. Then, first move the squares in the order of the list. If you move the block under the rail first, and then move the detector, the update from the detector causes the rail to fall as an item; then the piston continues to move the rail that does not exist according to the list, and places a new rail after it moves into place . In the same way, this method can also be used to replicate tiles such as carpets. I hope MOJANG can fix this bug as soon as possible