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 b44b18341331e5176e0f1851aa60cc425ccbd439..29834a3613c7701d46e879d170779eb7e6f664e1 100644
--- a/src/main/java/net/minecraft/world/entity/projectile/IProjectile.java
+++ b/src/main/java/net/minecraft/world/entity/projectile/IProjectile.java
@@ -45,7 +45,18 @@ 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