Weapons don't consume durability when attacking players blocking with shields

The Bug:

Weapons don't consume durability when attacking players blocking with shields.

If someone using a sword attacks another player that's blocking with a shield, the sword held by the attacker would not consume durability, and the shield held by the other player would.

Steps to Reproduce:

1. Get two players and label them, "Player A" and "Player B".
2. Get "Player A" to start blocking with a shield.
3. Get "Player B" to stand in front of "Player A", switch into survival mode, and obtain a sword.
4. Get "Player B" to attack "Player A" multiple times using the sword.
5. Get "Player B" to look at the durability of the sword.
6. Take note as to whether or not weapons consume durability when attacking players blocking with shields.

Observed Behavior:

Weapons don't consume durability.

Expected Behavior:

Weapons would consume durability.