Ignore Dead Entities in entityList iteration

A spigot change delays removal of entities from the entity list.
This causes a change in behavior from Vanilla where getEntities type
methods will return dead entities that they shouldn't otherwise be doing.

This will ensure that dead entities are skipped from iteration since
they shouldn't of been in the list in the first place.

Spigot-Server-Patches/0343-Ignore-Dead-Entities-in-entityList-iteration.patch

@@ -0,0 +1,103 @@
+From 3e0a26eb873fcf1fa259f775320ae0a6a6346ec0 Mon Sep 17 00:00:00 2001
+From: Aikar <aikar@aikar.co>
+Date: Sat, 28 Jul 2018 12:18:27 -0400
+Subject: [PATCH] Ignore Dead Entities in entityList iteration
+
+A spigot change delays removal of entities from the entity list.
+This causes a change in behavior from Vanilla where getEntities type
+methods will return dead entities that they shouldn't otherwise be doing.
+
+This will ensure that dead entities are skipped from iteration since
+they shouldn't of been in the list in the first place.
+
+diff --git a/src/main/java/com/destroystokyo/paper/PaperCommand.java b/src/main/java/com/destroystokyo/paper/PaperCommand.java
+index ecd1c65a9..1898ab897 100644
+--- a/src/main/java/com/destroystokyo/paper/PaperCommand.java
++++ b/src/main/java/com/destroystokyo/paper/PaperCommand.java
+@@ -128,6 +128,7 @@ public class PaperCommand extends Command {
+                 List<Entity> entities = world.entityList;
+                 entities.forEach(e -> {
+                     MinecraftKey key = EntityTypes.getKey(e);
++                    if (e.shouldBeRemoved) return; // Paper
+ 
+                     MutablePair<Integer, Map<ChunkCoordIntPair, Integer>> info = list.computeIfAbsent(key, k -> MutablePair.of(0, Maps.newHashMap()));
+                     ChunkCoordIntPair chunk = new ChunkCoordIntPair(e.getChunkX(), e.getChunkZ());
+diff --git a/src/main/java/net/minecraft/server/Entity.java b/src/main/java/net/minecraft/server/Entity.java
+index 89f9bd347..d163acd8f 100644
+--- a/src/main/java/net/minecraft/server/Entity.java
++++ b/src/main/java/net/minecraft/server/Entity.java
+@@ -124,6 +124,7 @@ public abstract class Entity implements ICommandListener, KeyedObject { // Paper
+     protected boolean E;
+     private boolean aw;
+     public boolean dead;
++    public boolean shouldBeRemoved; // Paper
+     public float width;
+     public float length;
+     public float I;
+diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
+index df98a4f44..8f82fbf67 100644
+--- a/src/main/java/net/minecraft/server/World.java
++++ b/src/main/java/net/minecraft/server/World.java
+@@ -1279,6 +1279,7 @@ public abstract class World implements IBlockAccess {
+         if (entity.aa && this.isChunkLoaded(i, j, true)) {
+             this.getChunkAt(i, j).b(entity);
+         }
++        entity.shouldBeRemoved = true; // Paper
+ 
+         if (!guardEntityList) { // Spigot - It will get removed after the tick if we are ticking // Paper - always remove from current chunk above
+         // CraftBukkit start - Decrement loop variable field if we've already ticked this entity
+@@ -2633,6 +2634,7 @@ public abstract class World implements IBlockAccess {
+ 
+         while (iterator.hasNext()) {
+             Entity entity = (Entity) iterator.next();
++            if (entity.shouldBeRemoved) continue; // Paper
+ 
+             if (oclass.isAssignableFrom(entity.getClass()) && predicate.apply((T) entity)) {
+                 arraylist.add(entity);
+@@ -2719,6 +2721,7 @@ public abstract class World implements IBlockAccess {
+ 
+         while (iterator.hasNext()) {
+             Entity entity = (Entity) iterator.next();
++            if (entity.shouldBeRemoved) continue; // Paper
+             // CraftBukkit start - Split out persistent check, don't apply it to special persistent mobs
+             if (entity instanceof EntityInsentient) {
+                 EntityInsentient entityinsentient = (EntityInsentient) entity;
+diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+index 210e3bc4e..e6ecd1796 100644
+--- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
++++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+@@ -678,6 +678,7 @@ public class CraftWorld implements World {
+         for (Object o : world.entityList) {
+             if (o instanceof net.minecraft.server.Entity) {
+                 net.minecraft.server.Entity mcEnt = (net.minecraft.server.Entity) o;
++                if (mcEnt.shouldBeRemoved) continue; // Paper
+                 Entity bukkitEntity = mcEnt.getBukkitEntity();
+ 
+                 // Assuming that bukkitEntity isn't null
+@@ -696,6 +697,7 @@ public class CraftWorld implements World {
+         for (Object o : world.entityList) {
+             if (o instanceof net.minecraft.server.Entity) {
+                 net.minecraft.server.Entity mcEnt = (net.minecraft.server.Entity) o;
++                if (mcEnt.shouldBeRemoved) continue; // Paper
+                 Entity bukkitEntity = mcEnt.getBukkitEntity();
+ 
+                 // Assuming that bukkitEntity isn't null
+@@ -720,6 +722,7 @@ public class CraftWorld implements World {
+ 
+         for (Object entity: world.entityList) {
+             if (entity instanceof net.minecraft.server.Entity) {
++                if (((net.minecraft.server.Entity) entity).shouldBeRemoved) continue; // Paper
+                 Entity bukkitEntity = ((net.minecraft.server.Entity) entity).getBukkitEntity();
+ 
+                 if (bukkitEntity == null) {
+@@ -742,6 +745,7 @@ public class CraftWorld implements World {
+ 
+         for (Object entity: world.entityList) {
+             if (entity instanceof net.minecraft.server.Entity) {
++                if (((net.minecraft.server.Entity) entity).shouldBeRemoved) continue; // Paper
+                 Entity bukkitEntity = ((net.minecraft.server.Entity) entity).getBukkitEntity();
+ 
+                 if (bukkitEntity == null) {
+-- 
+2.18.0
+