testserver/Spigot-Server-Patches/0254-Ignore-Dead-Entities-in-entityList-iteration.patch

From 0000000000000000000000000000000000000000 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 9cb2f3b31921870ddba044840e99eb04babe26bb..f0a836db74ad3e20778d3863223bc9a35ff4ad41 100644
--- a/src/main/java/com/destroystokyo/paper/PaperCommand.java
+++ b/src/main/java/com/destroystokyo/paper/PaperCommand.java
@@ -179,6 +179,7 @@ public class PaperCommand extends Command {
                 Collection<Entity> entities = world.entitiesById.values();
                 entities.forEach(e -> {
                     MinecraftKey key = e.getMinecraftKey();
+                    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.chunkX, e.chunkZ);
diff --git a/src/main/java/net/minecraft/server/Chunk.java b/src/main/java/net/minecraft/server/Chunk.java
index 8b9454fd44fe1d14eb6d46f772be56937c99595a..a35cd4df85f0043b83f2f70cec6091d6bae89767 100644
--- a/src/main/java/net/minecraft/server/Chunk.java
+++ b/src/main/java/net/minecraft/server/Chunk.java
@@ -823,6 +823,7 @@ public class Chunk implements IChunkAccess {
 
             for (int i1 = 0; i1 < l; ++i1) {
                 Entity entity1 = (Entity) list1.get(i1);
+                if (entity1.shouldBeRemoved) continue; // Paper
 
                 if (entity1.getBoundingBox().c(axisalignedbb) && entity1 != entity) {
                     if (predicate == null || predicate.test(entity1)) {
@@ -860,6 +861,7 @@ public class Chunk implements IChunkAccess {
 
             while (iterator.hasNext()) {
                 T entity = (T) iterator.next(); // CraftBukkit - decompile error
+                if (entity.shouldBeRemoved) continue; // Paper
 
                 if ((entitytypes == null || entity.getEntityType() == entitytypes) && entity.getBoundingBox().c(axisalignedbb) && predicate.test(entity)) {
                     list.add(entity);
@@ -882,6 +884,7 @@ public class Chunk implements IChunkAccess {
 
             while (iterator.hasNext()) {
                 T t0 = (T) iterator.next(); // CraftBukkit - decompile error
+                if (t0.shouldBeRemoved) continue; // Paper
 
                 if (oclass.isInstance(t0) && t0.getBoundingBox().c(axisalignedbb) && (predicate == null || predicate.test(t0))) { // Spigot - instance check
                     list.add(t0);
diff --git a/src/main/java/net/minecraft/server/Entity.java b/src/main/java/net/minecraft/server/Entity.java
index a331a62be48c3d9f5247817dfeeaba923aed5f57..769fada8ffa657493e5d7bf025281ff5f9f4299f 100644
--- a/src/main/java/net/minecraft/server/Entity.java
+++ b/src/main/java/net/minecraft/server/Entity.java
@@ -190,6 +190,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
     protected int numCollisions = 0; // Paper
     public void inactiveTick() { }
     // Spigot end
+    public boolean shouldBeRemoved; // Paper
 
     public float getBukkitYaw() {
         return this.yaw;
diff --git a/src/main/java/net/minecraft/server/WorldServer.java b/src/main/java/net/minecraft/server/WorldServer.java
index d6c319c1177e43eebeb7d9f366da3495b38b6b97..1cbb1c3ddf45cd6d650ca274af4545f2d1c8a813 100644
--- a/src/main/java/net/minecraft/server/WorldServer.java
+++ b/src/main/java/net/minecraft/server/WorldServer.java
@@ -1198,6 +1198,7 @@ public class WorldServer extends World implements GeneratorAccessSeed {
                 entity.origin = entity.getBukkitEntity().getLocation();
             }
             // Paper end
+            entity.shouldBeRemoved = false; // Paper - shouldn't be removed after being re-added
             new com.destroystokyo.paper.event.entity.EntityAddToWorldEvent(entity.getBukkitEntity()).callEvent(); // Paper - fire while valid
         }
 
@@ -1210,6 +1211,7 @@ public class WorldServer extends World implements GeneratorAccessSeed {
             this.removeEntityFromChunk(entity);
             this.entitiesById.remove(entity.getId());
             this.unregisterEntity(entity);
+            entity.shouldBeRemoved = true; // Paper
         }
     }
 
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
index cd0a59c3c88a0d7aa4d79acb473ad5da1c465072..9e9b9b9f81f1e4340b98724ca50fb03f699a03cb 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
@@ -1027,6 +1027,7 @@ public class CraftWorld implements World {
         for (Object o : world.entitiesById.values()) {
             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
@@ -1046,6 +1047,7 @@ public class CraftWorld implements World {
         for (Object o : world.entitiesById.values()) {
             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
@@ -1072,6 +1074,7 @@ public class CraftWorld implements World {
 
         for (Object entity: world.entitiesById.values()) {
             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) {
@@ -1095,6 +1098,7 @@ public class CraftWorld implements World {
 
         for (Object entity: world.entitiesById.values()) {
             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) {