Don't run entity collision code if not needed

patches/server/0120-Don-t-run-entity-collision-code-if-not-needed.patch

@@ -0,0 +1,36 @@
+From 0ddb705a9b56c7a1967ab659cfaad2094e441de1 Mon Sep 17 00:00:00 2001
+From: Spottedleaf <spottedleaf@spottedleaf.dev>
+Date: Thu, 26 Mar 2020 18:34:18 -0700
+Subject: [PATCH] Don't run entity collision code if not needed
+
+Will not run if max entity craming is disabled and
+the max collisions per entity is less than or equal to 0
+---
+ src/main/java/net/minecraft/server/EntityLiving.java | 8 +++++++-
+ 1 file changed, 7 insertions(+), 1 deletion(-)
+
+diff --git a/src/main/java/net/minecraft/server/EntityLiving.java b/src/main/java/net/minecraft/server/EntityLiving.java
+index 2769077bb4..a991614408 100644
+--- a/src/main/java/net/minecraft/server/EntityLiving.java
++++ b/src/main/java/net/minecraft/server/EntityLiving.java
+@@ -2689,10 +2689,16 @@ public abstract class EntityLiving extends Entity {
+     protected void doTick() {}
+ 
+     protected void collideNearby() {
++        // Purpur start
++        int i = this.world.getGameRules().getInt(GameRules.MAX_ENTITY_CRAMMING);
++        if (i <= 0 && world.paperConfig.maxCollisionsPerEntity <= 0) {
++            return;
++        }
++        // Purpur end
+         List<Entity> list = this.world.getEntities(this, this.getBoundingBox(), IEntitySelector.pushable(this, world.purpurConfig.fixClimbingBypassingCrammingRule)); // Purpur
+ 
+         if (!list.isEmpty()) {
+-            int i = this.world.getGameRules().getInt(GameRules.MAX_ENTITY_CRAMMING);
++            // int i = this.world.getGameRules().getInt(GameRules.MAX_ENTITY_CRAMMING); // Purpur - move up
+             int j;
+ 
+             if (i > 0 && list.size() > i - 1 && this.random.nextInt(4) == 0) {
+-- 
+2.24.0
+