When spamming, damage is negated but durability is affected

Summary:

When spamming attack on a mob, some damage is negated/ignored but the durability is still affected.

Steps To Produce

1. Obtain a tool in your minecraft world

2. find a mob

3. spam hit that mob and count how many hits it took to kill 
    it

4. then find the same mob and hit it slowly, then record how many hits it took to kill it

5. Record your findings

What Happends (Problem):

Footage 1:

Footage 2:{*}{*}

What Should Happen ( Solution):

No matter how much you spam, the damage should still be installed ( Since we dont have the combat update)/applied.