Cap Entity Collisions

Limit a single entity to colliding a max of configurable times per tick.
This will alleviate issues where living entities are hoarded in 1x1 pens.

CraftBukkit-Patches/0107-Cap-Entity-Collisions.patch

@@ -0,0 +1,65 @@
+From 17ee69deb13c9e1861411aef9879ff667ed5ad25 Mon Sep 17 00:00:00 2001
+From: Aikar <aikar@aikar.co>
+Date: Fri, 31 Jan 2014 11:18:34 -0500
+Subject: [PATCH] Cap Entity Collisions
+
+Limit a single entity to colliding a max of configurable times per tick.
+This will alleviate issues where living entities are hoarded in 1x1 pens.
+
+diff --git a/src/main/java/net/minecraft/server/Entity.java b/src/main/java/net/minecraft/server/Entity.java
+index e147244..cd621c4 100644
+--- a/src/main/java/net/minecraft/server/Entity.java
++++ b/src/main/java/net/minecraft/server/Entity.java
+@@ -1020,6 +1020,7 @@ public abstract class Entity {
+ 
+     public void b_(EntityHuman entityhuman) {}
+ 
++    int numCollisions = 0; // Spigot
+     public void collide(Entity entity) {
+         if (entity.passenger != this && entity.vehicle != this) {
+             double d0 = entity.locX - this.locX;
+diff --git a/src/main/java/net/minecraft/server/EntityLiving.java b/src/main/java/net/minecraft/server/EntityLiving.java
+index 35b2f75..ab28bd3 100644
+--- a/src/main/java/net/minecraft/server/EntityLiving.java
++++ b/src/main/java/net/minecraft/server/EntityLiving.java
+@@ -1486,7 +1486,9 @@ public abstract class EntityLiving extends Entity {
+         List list = this.world.getEntities(this, this.boundingBox.grow(0.20000000298023224D, 0.0D, 0.20000000298023224D));
+ 
+         if (this.R() && list != null && !list.isEmpty()) { // Spigot: Add this.R() condition
++            numCollisions -= world.spigotConfig.maxCollisionsPerEntity; // Spigot
+             for (int i = 0; i < list.size(); ++i) {
++                if (numCollisions > world.spigotConfig.maxCollisionsPerEntity) { break; } // Spigot
+                 Entity entity = (Entity) list.get(i);
+ 
+                 // TODO better check now?
+@@ -1497,9 +1499,12 @@ public abstract class EntityLiving extends Entity {
+                 // CraftBukkit end
+ 
+                 if (entity.S()) {
++                    entity.numCollisions++; // Spigot
++                    numCollisions++; // Spigot
+                     this.n(entity);
+                 }
+             }
++            numCollisions = 0; // Spigot
+         }
+     }
+ 
+diff --git a/src/main/java/org/spigotmc/SpigotWorldConfig.java b/src/main/java/org/spigotmc/SpigotWorldConfig.java
+index 4cff009..8f23103 100644
+--- a/src/main/java/org/spigotmc/SpigotWorldConfig.java
++++ b/src/main/java/org/spigotmc/SpigotWorldConfig.java
+@@ -271,4 +271,10 @@ public class SpigotWorldConfig
+         maxBulkChunk = getInt( "max-bulk-chunks", 5 );
+         log( "Sending up to " + maxBulkChunk + " chunks per packet" );
+     }
++
++    public int maxCollisionsPerEntity = 8;
++    private void maxEntityCollision() {
++        maxCollisionsPerEntity = getInt( "max-entity-collisions", maxCollisionsPerEntity );
++        log( "Max Entity Collisions: " + maxCollisionsPerEntity );
++    }
+ }
+-- 
+1.8.3.2
+