The Bug:

Armor stands hit by indirect sweeping attacks receive knockback.

Steps to Reproduce:

1. Place three armor stands next to one another and obtain a sword.
2. Stand still and hit the armor stand in the middle with a sweeping attack.
3. Observe the behavior of the two armor stands that you didn't directly attack.

Observed Behavior:

Armor stands hit by indirect sweeping attacks receive knockback.

Expected Behavior:

Armor stands hit by indirect sweeping attacks would not receive knockback.