Breaking an armor stand or block-attached entity near a sculk catalyst consumes the player's experience

The bug

If a player breaks an armor stand, cushion, painting, or item frame near a sculk catalyst, the game treats it as though the player was the entity that died. The catalyst blooms and spreads sculk in proportion to the player’s experience points, and the player is flagged to no longer drop experience on death, or interact with future catalysts. This state does not persist relog, however, so you can farm infinite sculk by simply placing and breaking cushions, then relogging.

How to reproduce

1. /xp add @s 100 levels

2. Place a sculk catalyst

3. Place a cushion

4. Break it

Expected result

Nothing should happen

Observed result

The sculk catalyst blooms and spreads

Code analysis

In 26.3-snapshot-8, a small refactor to kill handling was performed, and ArmorStand.kill and BlockAttachedEntity.kill were given logic to pass the responsible entity to Entity.gameEvent instead of the dying entity. This is incorrect. As a result, SculkCatalystBlockEntity.handleGameEvent receives the player in sourceEntity and consumes its experience, instead of receiving the armor stand or cushion and correctly stopping.

https://mcsrc.dev/2/diff/26.3-snapshot-7/26.3-snapshot-8/net/minecraft/world/entity/decoration/ArmorStand#R467

https://mcsrc.dev/2/diff/26.3-snapshot-7/26.3-snapshot-8/net/minecraft/world/entity/decoration/BlockAttachedEntity#R84