When Crafting an item that consists of only one item,the item in the crafting table will not be consumed

When Crafting an item that consists of only one item,the item in the crafting table will not be consumed

What I expected to happen was...:
Will consume the item.

What actually happened was...:

The item won't be consumed.

Steps to Reproduce:
1. put a diamond block in the crafting table(the item must be in the middle of the crafting table)
2. take the diamonds
3. the diamond block isn't disappered!