From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Sun, 10 May 2020 22:12:46 -0400
Subject: [PATCH] Ensure Entity AABB's are never invalid


diff --git a/src/main/java/net/minecraft/server/Entity.java b/src/main/java/net/minecraft/server/Entity.java
index af9f906b4eb806c73f8ec98ea562393c2b48419e..759a91f43c9890602f4bb372eb241ebc0128b310 100644
--- a/src/main/java/net/minecraft/server/Entity.java
+++ b/src/main/java/net/minecraft/server/Entity.java
@@ -1,53 +1,54 @@
 package net.minecraft.server;
 
+import co.aikar.timings.MinecraftTimings;
+import co.aikar.timings.Timing;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Sets;
 import it.unimi.dsi.fastutil.objects.Object2DoubleArrayMap;
 import it.unimi.dsi.fastutil.objects.Object2DoubleMap;
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.Iterator;
-import java.util.List;
-import java.util.Locale;
-import java.util.Optional;
-import java.util.Random;
-import java.util.Set;
-import java.util.UUID;
-import java.util.concurrent.atomic.AtomicInteger;
-import java.util.stream.Stream;
-import javax.annotation.Nullable;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
-
-// CraftBukkit start
 import org.bukkit.Bukkit;
 import org.bukkit.Server;
 import org.bukkit.block.BlockFace;
 import org.bukkit.command.CommandSender;
-import org.bukkit.entity.Hanging;
-import org.bukkit.entity.LivingEntity;
-import org.bukkit.entity.Vehicle;
-import co.aikar.timings.MinecraftTimings; // Paper
-import co.aikar.timings.Timing; // Paper
-import org.bukkit.event.entity.EntityCombustByEntityEvent;
-import org.bukkit.event.hanging.HangingBreakByEntityEvent;
-import org.bukkit.event.vehicle.VehicleBlockCollisionEvent;
-import org.bukkit.event.vehicle.VehicleEnterEvent;
-import org.bukkit.event.vehicle.VehicleExitEvent;
 import org.bukkit.craftbukkit.CraftWorld;
 import org.bukkit.craftbukkit.entity.CraftEntity;
 import org.bukkit.craftbukkit.entity.CraftPlayer;
 import org.bukkit.craftbukkit.event.CraftEventFactory;
+import org.bukkit.entity.Hanging;
+import org.bukkit.entity.LivingEntity;
 import org.bukkit.entity.Pose;
+import org.bukkit.entity.Vehicle;
 import org.bukkit.event.entity.EntityAirChangeEvent;
+import org.bukkit.event.entity.EntityCombustByEntityEvent;
 import org.bukkit.event.entity.EntityCombustEvent;
 import org.bukkit.event.entity.EntityDropItemEvent;
 import org.bukkit.event.entity.EntityPortalEvent;
 import org.bukkit.event.entity.EntityPoseChangeEvent;
+import org.bukkit.event.hanging.HangingBreakByEntityEvent;
 import org.bukkit.event.player.PlayerTeleportEvent;
+import org.bukkit.event.vehicle.VehicleBlockCollisionEvent;
+import org.bukkit.event.vehicle.VehicleEnterEvent;
+import org.bukkit.event.vehicle.VehicleExitEvent;
 import org.bukkit.plugin.PluginManager;
+
+import javax.annotation.Nullable;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Locale;
+import java.util.Optional;
+import java.util.Random;
+import java.util.Set;
+import java.util.UUID;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.stream.Stream;
+
+// CraftBukkit start
 // CraftBukkit end
 
 public abstract class Entity implements INamableTileEntity, ICommandListener, KeyedObject { // Paper
@@ -425,10 +426,12 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
 
     public void setPosition(double d0, double d1, double d2) {
         this.setPositionRaw(d0, d1, d2);
-        float f = this.size.width / 2.0F;
-        float f1 = this.size.height;
+        // Paper start - move into setPositionRaw
+        //float f = this.size.width / 2.0F;
+        //float f1 = this.size.height;
 
-        this.a(new AxisAlignedBB(d0 - (double) f, d1, d2 - (double) f, d0 + (double) f, d1 + (double) f1, d2 + (double) f));
+        //this.a(new AxisAlignedBB(d0 - (double) f, d1, d2 - (double) f, d0 + (double) f, d1 + (double) f1, d2 + (double) f));
+        // Paper end
         if (valid) ((WorldServer) world).chunkCheck(this); // CraftBukkit
     }
 
@@ -2907,6 +2910,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
         return new AxisAlignedBB(vec3d, vec3d1);
     }
 
+    public final void setBoundingBox(AxisAlignedBB axisalignedbb) { a(axisalignedbb); } // Paper - OBFHELPER
     public void a(AxisAlignedBB axisalignedbb) {
         // CraftBukkit start - block invalid bounding boxes
         double minX = axisalignedbb.minX,
@@ -3345,6 +3349,14 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
     }
 
     public void setPositionRaw(double d0, double d1, double d2) {
+        // Paper start - never allow AABB to become desynced from position
+        // hanging has its own special logic
+        if (!(this instanceof EntityHanging) && (this.loc.x != d0 || this.loc.y != d1 || this.loc.z != d2)) {
+            float f = this.size.width / 2.0F;
+            float f1 = this.size.height;
+            this.setBoundingBox(new AxisAlignedBB(d0 - (double) f, d1, d2 - (double) f, d0 + (double) f, d1 + (double) f1, d2 + (double) f));
+        }
+        // Paper end
         if (this.loc.x != d0 || this.loc.y != d1 || this.loc.z != d2) {
             this.loc = new Vec3D(d0, d1, d2);
             int i = MathHelper.floor(d0);