don't attempt to teleport dead entities (#6832)

patches/server/0835-don-t-attempt-to-teleport-dead-entities.patch

@@ -0,0 +1,19 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: sulu5890 <sulu@sulu.me>
+Date: Sun, 24 Oct 2021 22:48:14 -0500
+Subject: [PATCH] don't attempt to teleport dead entities
+
+
+diff --git a/src/main/java/net/minecraft/world/entity/Entity.java b/src/main/java/net/minecraft/world/entity/Entity.java
+index e17bda0d13bae337cfad5ae31b118aa7a85499fc..2ce32495758abf64eeeeeea1cdbf4904be77b697 100644
+--- a/src/main/java/net/minecraft/world/entity/Entity.java
++++ b/src/main/java/net/minecraft/world/entity/Entity.java
+@@ -702,7 +702,7 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource, n
+     // CraftBukkit start
+     public void postTick() {
+         // No clean way to break out of ticking once the entity has been copied to a new world, so instead we move the portalling later in the tick cycle
+-        if (!(this instanceof ServerPlayer)) {
++        if (!(this instanceof ServerPlayer) && this.isAlive()) { // Paper - don't attempt to teleport dead entities
+             this.handleNetherPortal();
+         }
+     }