A duplication bug occurs, making it possible to adventure to the Enderdragon easier.

Steps to reproduce:

1. Mark out a chunk using the debug screen. You can use any material (except the blocks around it) to mark the corners.
2.On one of the edges, use the same blocks to form a backwards L shape. On the back of the L, place an item frame. This must be in a different chunk than the block it is attached to.
3. Place a redstone comparator on the tip of the L, facing the item frame. It does not need to be active, though.
4. All that is left is to place the item you want to duplicate in the item frame and reload your world. And the item will be duplicated, aswell as the item frame itself.

To find more information, watch the video that The 8-bit monkey posted a couple of months ago. That's where I found out this bug.