If a player is in creative mode and places any item in an anvil with any enchanted book, it will enchant.

Previously doing this would result in a red “cannot enchant” symbol, preventing anything from happening. This also allows items to have enchants they are not supposed to have. However, in my testing, you cannot apply two incomparable enchantments (mending/infinity, for example).

How to recreate:

1. Create a world or enter an existing one.
2. Enter creative mode.
3. Get an anvil and place it on the ground.
4. Take any item, say a piece of dirt from the creative inventory and place it in your hot bar.
5. Take any enchanted book, say knockback 2, and place it in your hot bar.
6. Enter the anvil interface.
7. Place the item (dirt block) in the first slot of the interface.
8. Place the book in the second slot of the interface.
9. The enchantment is applied to the item.