Description
When shooting with a bow at the edge of the bounding box of a moving entity, there is a chance of the arrow getting deflected and upon landing it’s actual position gets updated (behind the mob, as if it did not hit, client-server desync)
Steps to Reproduce
Spawn a Husk (theoretically it’ll work for every hostile mob and most likely any moving Entity)
Let the Husk run towards you, while it does so shoot arrows at the top edge (head) of their bounding box
In some cases the arrow deflect (without the entity having damage immunity), it might take some tries to trigger this bug
Notes
Tested in singleplayer as well as on a localhost vanilla dedicated server (both having the issue)
I was not able to reproduce this without the entity moving
Tested in 1.21.8, 1.21.5, 1.21.3 (the issue is present in every version, however it’s much more noticeable in 1.21.6+ due to the projectile precision changes. In older version you need to aim way above the entity to trigger the bug)
This is different from MC-102732 which seems to take damage immunity as the cause of the issue. However this issue does not happen due to damage immunity, the arrow deflects without the entity being immune at the time the arrow hits. Furthermore unlike in the mentioned issue the arrow receives a position update upon landing (unlike in the mentioned bug report, where it stays at the deflected position)
This is different from MC-298762 as this issue is phrased to only happen on flying mobs or phantoms. However flying mobs (bats, phantoms) are mentioned in the other bug report as well?
Attached a video of me reproducing this bug in 1.21.8
Environment
Linux
Linked issues
is duplicated by 1
relates to 3
Attachments
Comments 2
I believe this issue might be related to MC-298762 (similar behaviour), but I’m not completely sure. Just mentioning it in case it helps with the tracking.
I was able to reproduce this on version 1.21.10 with other entities as well, zombies and other mobs with similarly shaped hitboxes seem better suited for this, because their head or the top of their hitbox is at the height of the player. Shorter hitboxes seem to require player to be lower for the arrows to collide with the hitbox a similar way.
Wind charges and eggs also seem to have similarly odd behaviour, but especially with the latter the bug is harder to reproduce. Both stop in the air but do not bounce like arrows do. Both require the mobs to be moving and occur when attempting to hit near the top of the hitbox.