Paper/patches/server/0409-Ensure-Entity-AABB-s-are-never-invalid.patch

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/world/entity/Entity.java b/src/main/java/net/minecraft/world/entity/Entity.java
index a1d990aa2e79af9e1ff078892cdb38a382f21da7..a1172531baf637915a65fbdee8ca08f08034811d 100644
--- a/src/main/java/net/minecraft/world/entity/Entity.java
+++ b/src/main/java/net/minecraft/world/entity/Entity.java
@@ -728,8 +728,8 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource, S
     }
 
     public void setPos(double x, double y, double z) {
-        this.setPosRaw(x, y, z);
-        this.setBoundingBox(this.makeBoundingBox());
+        this.setPosRaw(x, y, z, true); // Paper - force bounding box update
+        // this.setBoundingBox(this.makeBoundingBox()); // Paper - move into setPositionRaw
     }
 
     protected AABB makeBoundingBox() {
@@ -4244,6 +4244,11 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource, S
     }
 
     public final void setPosRaw(double x, double y, double z) {
+        // Paper start
+        this.setPosRaw(x, y, z, false);
+    }
+    public final void setPosRaw(double x, double y, double z, boolean forceBoundingBoxUpdate) {
+        // Paper end
         // Paper start - rewrite chunk system
         if (this.updatingSectionStatus) {
             LOGGER.error("Refusing to update position for entity " + this + " to position " + new Vec3(x, y, z) + " since it is processing a section status update", new Throwable());
@@ -4267,6 +4272,12 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource, S
             this.levelCallback.onMove();
         }
 
+        // Paper start - never allow AABB to become desynced from position
+        // hanging has its own special logic
+        if (!(this instanceof net.minecraft.world.entity.decoration.HangingEntity) && (forceBoundingBoxUpdate || this.position.x != x || this.position.y != y || this.position.z != z)) {
+            this.setBoundingBox(this.makeBoundingBox());
+        }
+        // Paper end
     }
 
     public void checkDespawn() {}