From 06f64c95ff6f0e07d8fffa60b551ecf7e32700a1 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Mon, 28 Mar 2016 19:55:45 -0400
Subject: [PATCH] Only process BlockPhysicsEvent if a plugin has a listener

Saves on some object allocation and processing when no plugin listens to this

diff --git a/src/main/java/net/minecraft/server/BlockPlant.java b/src/main/java/net/minecraft/server/BlockPlant.java
index 0e4037ea21..317ae16347 100644
--- a/src/main/java/net/minecraft/server/BlockPlant.java
+++ b/src/main/java/net/minecraft/server/BlockPlant.java
@@ -15,7 +15,7 @@ public class BlockPlant extends Block {
     public IBlockData updateState(IBlockData iblockdata, EnumDirection enumdirection, IBlockData iblockdata1, GeneratorAccess generatoraccess, BlockPosition blockposition, BlockPosition blockposition1) {
         // CraftBukkit start
         if (!iblockdata.canPlace(generatoraccess, blockposition)) {
-            if (!org.bukkit.craftbukkit.event.CraftEventFactory.callBlockPhysicsEvent(generatoraccess, blockposition).isCancelled()) {
+            if (!(generatoraccess instanceof WorldServer && ((WorldServer) generatoraccess).hasPhysicsEvent) || !org.bukkit.craftbukkit.event.CraftEventFactory.callBlockPhysicsEvent(generatoraccess, blockposition).isCancelled()) { // Paper
                 return Blocks.AIR.getBlockData();
             }
         }
diff --git a/src/main/java/net/minecraft/server/BlockTallPlant.java b/src/main/java/net/minecraft/server/BlockTallPlant.java
index 77782bf1c1..39d449c28e 100644
--- a/src/main/java/net/minecraft/server/BlockTallPlant.java
+++ b/src/main/java/net/minecraft/server/BlockTallPlant.java
@@ -49,7 +49,7 @@ public class BlockTallPlant extends BlockPlant {
 
     public void a(World world, BlockPosition blockposition, IBlockData iblockdata, EntityHuman entityhuman) {
         // CraftBukkit start
-        if (org.bukkit.craftbukkit.event.CraftEventFactory.callBlockPhysicsEvent(world, blockposition).isCancelled()) {
+        if (((WorldServer)world).hasPhysicsEvent && org.bukkit.craftbukkit.event.CraftEventFactory.callBlockPhysicsEvent(world, blockposition).isCancelled()) { // Paper
             return;
         }
         // CraftBukkit end
diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index f488c37f73..ee45d3705b 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -1001,6 +1001,7 @@ public abstract class MinecraftServer implements IAsyncTaskHandler, IMojangStati
         // CraftBukkit - dropTickTime
         for (Iterator iterator = this.getWorlds().iterator(); iterator.hasNext();) {
              WorldServer worldserver = (WorldServer) iterator.next();
+            worldserver.hasPhysicsEvent =  org.bukkit.event.block.BlockPhysicsEvent.getHandlerList().getRegisteredListeners().length > 0; // Paper
             i = SystemUtils.getMonotonicNanos();
             if (true || worldserver.worldProvider.getDimensionManager() == DimensionManager.OVERWORLD || this.getAllowNether()) { // CraftBukkit
                 this.methodProfiler.a(() -> {
diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
index b398dd1b57..87ea698eec 100644
--- a/src/main/java/net/minecraft/server/World.java
+++ b/src/main/java/net/minecraft/server/World.java
@@ -486,7 +486,7 @@ public abstract class World implements IEntityAccess, GeneratorAccess, IIBlockAc
                 // CraftBukkit start
                 iblockdata1.b(this, blockposition, j); // Don't call an event for the old block to limit event spam
                 CraftWorld world = ((WorldServer) this).getWorld();
-                if (world != null) {
+                if (world != null && ((WorldServer)this).hasPhysicsEvent) { // Paper
                     BlockPhysicsEvent event = new BlockPhysicsEvent(world.getBlockAt(blockposition.getX(), blockposition.getY(), blockposition.getZ()), CraftBlockData.fromData(iblockdata));
                     this.getServer().getPluginManager().callEvent(event);
 
@@ -620,7 +620,7 @@ public abstract class World implements IEntityAccess, GeneratorAccess, IIBlockAc
             try {
                 // CraftBukkit start
                 CraftWorld world = ((WorldServer) this).getWorld();
-                if (world != null) {
+                if (world != null && ((WorldServer)this).hasPhysicsEvent) { // Paper
                     BlockPhysicsEvent event = new BlockPhysicsEvent(world.getBlockAt(blockposition.getX(), blockposition.getY(), blockposition.getZ()), CraftBlockData.fromData(iblockdata), world.getBlockAt(blockposition1.getX(), blockposition1.getY(), blockposition1.getZ()));
                     this.getServer().getPluginManager().callEvent(event);
 
diff --git a/src/main/java/net/minecraft/server/WorldServer.java b/src/main/java/net/minecraft/server/WorldServer.java
index aaeb888a8c..639068d2dc 100644
--- a/src/main/java/net/minecraft/server/WorldServer.java
+++ b/src/main/java/net/minecraft/server/WorldServer.java
@@ -33,6 +33,7 @@ import org.bukkit.event.weather.LightningStrikeEvent;
 public class WorldServer extends World implements IAsyncTaskHandler {
 
     private static final Logger a = LogManager.getLogger();
+    boolean hasPhysicsEvent = true; // Paper
     private final MinecraftServer server;
     public EntityTracker tracker;
     private final PlayerChunkMap manager;
-- 
2.21.0