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/IProjectile.java b/src/main/java/net/minecraft/world/entity/projectile/IProjectile.java
index 65cee640040bdd1229149409ff046b765ee08c34..a33f3924a95b86c2337c455f30de9bb257cb8db4 100644
--- a/src/main/java/net/minecraft/world/entity/projectile/IProjectile.java
+++ b/src/main/java/net/minecraft/world/entity/projectile/IProjectile.java
@@ -41,7 +41,18 @@ public abstract class IProjectile extends Entity {
 
     @Nullable
     public Entity getShooter() {
-        return this.shooter != null && this.world instanceof WorldServer ? ((WorldServer) this.world).getEntity(this.shooter) : (this.c != 0 ? this.world.getEntity(this.c) : null);
+        // Paper start - MC-50319 - shooter might be in another world (arrows through portals)
+        Entity entity = this.shooter != null && this.world instanceof WorldServer ? ((WorldServer) this.world).getEntity(this.shooter) : (this.c != 0 ? this.world.getEntity(this.c) : null);
+        if (entity == null) {
+            for (WorldServer world : world.getMinecraftServer().getWorlds()) {
+                entity = world.getEntity(this.shooter);
+                if (entity != null) {
+                    break;
+                }
+            }
+        }
+        return entity;
+        // Paper end
     }
 
     @Override