Paper/Spigot-Server-Patches/0529-Use-saner-Entity-bounding-box-limits.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Fri, 22 May 2020 00:29:52 -0400
Subject: [PATCH] Use saner Entity bounding box limits

CB only protected from > 64 but there's no reason an entity should ever
be more than 2x its width or 1x height as the BB is supposed to represent
the entity size.

BB is / 2 to calculate position.

diff --git a/src/main/java/net/minecraft/server/Entity.java b/src/main/java/net/minecraft/server/Entity.java
index e0ab058bf947ea10b37eadf6122292e708bd3809..76fcde33416995ef46693b75dc4484e13d3daf1f 100644
--- a/src/main/java/net/minecraft/server/Entity.java
+++ b/src/main/java/net/minecraft/server/Entity.java
@@ -2991,18 +2991,45 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
                 maxX = axisalignedbb.maxX,
                 maxY = axisalignedbb.maxY,
                 maxZ = axisalignedbb.maxZ;
+        // Paper start - use saner max's for bounding box
+        boolean illegal = false;
+        double maxW = this.getWidth() * 2;
+        double maxH = this.getHeight();
         double len = axisalignedbb.maxX - axisalignedbb.minX;
-        if (len < 0) maxX = minX;
-        if (len > 64) maxX = minX + 64.0;
+        if (len < 0) {
+            maxX = minX;
+            illegal = true;
+        }
+        if (len > maxW+1.0E-7D) {
+            maxX = minX + maxW;
+            illegal = true;
+        }
 
         len = axisalignedbb.maxY - axisalignedbb.minY;
-        if (len < 0) maxY = minY;
-        if (len > 64) maxY = minY + 64.0;
+        if (len < 0) {
+            maxY = minY;
+            illegal = true;
+        }
+        if (len > maxH+1.0E-7D) {
+            maxY = minY + maxH;
+            illegal = true;
+        }
 
         len = axisalignedbb.maxZ - axisalignedbb.minZ;
-        if (len < 0) maxZ = minZ;
-        if (len > 64) maxZ = minZ + 64.0;
+        if (len < 0) {
+            maxZ = minZ;
+            illegal = true;
+        }
+        if (len > maxW+1.0E-7D) {
+            maxZ = minZ + maxW;
+            illegal = true;
+        }
+
         this.boundingBox = new AxisAlignedBB(minX, minY, minZ, maxX, maxY, maxZ);
+        if (illegal) {
+            new Throwable("Illegal Entity bounding box attempt on (" + this + ") - tried: " + axisalignedbb + " - using: " + boundingBox).printStackTrace();
+        }
+        // Paper end
         // CraftBukkit end
     }