From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Wed, 17 Oct 2018 19:17:27 -0400
Subject: [PATCH] MC-50319: Check other worlds for shooter of projectiles

Say a player shoots an arrow through a nether portal, the game
would lose the shooter for determining things such as Player Kills,
because the entity is in another world.

If the projectile fails to find the shooter in the current world, check
other worlds.

diff --git a/src/main/java/net/minecraft/world/entity/projectile/Projectile.java b/src/main/java/net/minecraft/world/entity/projectile/Projectile.java
index d1dd173c11d751b15c3afd4309e386931fd9cf8d..d385fb6eee5000951c350b6ced5669dc3dcce725 100644
--- a/src/main/java/net/minecraft/world/entity/projectile/Projectile.java
+++ b/src/main/java/net/minecraft/world/entity/projectile/Projectile.java
@@ -44,7 +44,18 @@ public abstract class Projectile extends Entity {
 
     @Nullable
     public Entity getOwner() {
-        return this.ownerUUID != null && this.level instanceof ServerLevel ? ((ServerLevel) this.level).getEntity(this.ownerUUID) : (this.ownerNetworkId != 0 ? this.level.getEntity(this.ownerNetworkId) : null);
+        // Paper start - MC-50319 - shooter might be in another world (arrows through portals)
+        Entity entity = this.ownerUUID != null && this.level instanceof ServerLevel ? ((ServerLevel) this.level).getEntity(this.ownerUUID) : (this.ownerNetworkId != 0 ? this.level.getEntity(this.ownerNetworkId) : null);
+        if (entity == null) {
+            for (ServerLevel world : level.getServer().getAllLevels()) {
+                entity = world.getEntity(this.ownerUUID);
+                if (entity != null) {
+                    break;
+                }
+            }
+        }
+        return entity;
+        // Paper end
     }
 
     @Override