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/server/IProjectile.java b/src/main/java/net/minecraft/server/IProjectile.java
index f85d80d7bb3e4e92bb8d281dfe577f663ebe9da1..ceecb0520a63d2eff5f4cadf45fa49f56eaea8dd 100644
--- a/src/main/java/net/minecraft/server/IProjectile.java
+++ b/src/main/java/net/minecraft/server/IProjectile.java
@@ -29,7 +29,18 @@ 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