Please link MC-278088 to this.

Some items do not act synchronously in time after switching items.

Reproduce:

1. Prepare 2 different items in hot bar.
2. Switch item A to item B.
3. Perform the following operations through the item B immediately.

Tested operations:

Attack:

Item A: Fire aspect enchanted wooden sword

Item B: Diamond sword without enchantment

1. Spawn a villager and give it fire resistance to prevent fire damage changing the result
2. Hold the wooden sword and wait for 100% charge
3. Switch to the diamond sword and attack immediately

Result:

/data get entity @n[type=minecraft:villager] Health

The villager takes 100% damage of 4 Not meeting expectations

The villager isn't ignited Meet expectations

Item B 's durability decreases Meet expectations

Attack 2:

Item A: Diamond sword without enchantment

Item B: Fire aspect enchanted wooden sword

1. Spawn a villager and give it fire resistance to prevent fire damage changing the result
2. Hold the diamond sword and wait for 100% charge
3. Switch to the wooden sword and attack immediately

Result:

/data get entity @n[type=minecraft:villager] Health

The villager takes 100% damage of 7 Not meeting expectations

The villager is ignited Meet expectations

Item B 's durability decreases Meet expectations

Drop:

Item A: Diamond sword

Item B: Wooden sword

1. Hold the diamond sword
2. Switch to the wooden sword and drop immediately

Result:

(This must be tested in survival mode)

The wooden sword in hot bar disappears Meet expectations

But the dropped item on the ground is diamond sword Not meeting expectations

And I click the diamond sword slot, the diamond sword disappears.

I click the wooden sword slot, the wooden sword appears.

Building:

Tested items: dirt and stone, lava bucket and water bucket

Meet expectations

Using:

Tested items: egg and snowball, creeper spawner egg and zombie spawner egg, diamond hoe and wooden shovel

Meet expectations

Predicitons:
In my opinion, when switching items, the game did not reset the player's attack charging in a timely manner, nor did it modify the impact of items on the player's attributes in a timely manner