Relates to MC-270532 and MC-270568.

The bug

The player is blocked from causing direct damage to the entity it rides. However, attempting to ride something the player can pick up causes it to be picked up instantly, despite the fact this "kills" the entity in question.

How to reproduce

1. Drop an item on the ground

2. /ride @s mount @e[type=minecraft:item,limit=1,sort=nearest]

Expected results

The player would be blocked from picking up the item until dismounted, since this "harms" the entity.

Actual results

It is picked up instantly.