EntityDamageByBlockEvent.getDamager() returning null for lava

[Mitality]

Expected behavior

Up to version 1.21.1, EntityDamageByBlockEvent.getDamager() returns the block responsible for the damage dealt as a valid Block object for damage caused by lava. I therefore expected it to work that way in newer versions too, as it's most certainly the expected behavior of this method in this case.

Observed/Actual behavior

On 1.21.3+, EntityDamageByBlockEvent.getDamager() just returns null for damage caused by lava.

Steps/models to reproduce

Here's what I did:

• Create 2 localhost servers, one with PaperMC 1.21.1 and the other one with PaperMC 1.21.3 (newest builds).
  (no changes to those servers except accepting the eula)

• Create a minimalistic plugin to log EntityDamageByBlockEvent.getDamager().

• Join both servers, grab a bucket of lava and take a bath.

• Compare console output:
  1.21.1: CraftBlock{...}
  1.21.3: null

Plugin and Datapack List

Just the minimalistic logging plugin:

public final class GetDamagerTest extends JavaPlugin implements Listener {

    @Override
    public void onEnable() {
        getServer().getPluginManager().registerEvents(this, this);
    }

    @Override
    public void onDisable() {}

    @EventHandler
    public void onDamageByBlock(EntityDamageByBlockEvent event) {
        Bukkit.getLogger().info(event.getDamager());
    }
}

Paper version

1.21.1#132 & 1.21.3#82

Other

No response

[lynxplay]

Caused by the moonrise patch, patching over CB setting Entity.lastLavaContact in Entity#updateFluidHeightAndDoFluidPushing

Might be worth looking for a better alternative to this field tho (if there is one)