From 0000000000000000000000000000000000000000 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/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index 21e09c039a4c3fa64f6456e5cc7d50463590f787..cfbf7efb06f7ed6064930c4154c6e3e949dc0b25 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -1355,6 +1355,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
 
         while (iterator.hasNext()) {
             ServerLevel worldserver = (ServerLevel) iterator.next();
+            worldserver.hasPhysicsEvent =  org.bukkit.event.block.BlockPhysicsEvent.getHandlerList().getRegisteredListeners().length > 0; // Paper
 
             this.profiler.push(() -> {
                 return worldserver + " " + worldserver.dimension().location();
diff --git a/src/main/java/net/minecraft/server/level/ServerLevel.java b/src/main/java/net/minecraft/server/level/ServerLevel.java
index 6b85a9ee89bf2f01385aa0d3aab2e92325381021..868db73e815a59f7f917de64f3cc45d89f5b6bb5 100644
--- a/src/main/java/net/minecraft/server/level/ServerLevel.java
+++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
@@ -213,6 +213,7 @@ public class ServerLevel extends Level implements WorldGenLevel {
     // CraftBukkit start
     public final LevelStorageSource.LevelStorageAccess convertable;
     public final UUID uuid;
+    public boolean hasPhysicsEvent = true; // Paper
 
     @Override public LevelChunk getChunkIfLoaded(int x, int z) { // Paper - this was added in world too but keeping here for NMS ABI
         return this.chunkSource.getChunk(x, z, false);
diff --git a/src/main/java/net/minecraft/world/level/Level.java b/src/main/java/net/minecraft/world/level/Level.java
index 7c058e32b83847625bd4136bfed9b5804e8beca7..46c7c63d4dced4e75079588cef2c155859e5ae36 100644
--- a/src/main/java/net/minecraft/world/level/Level.java
+++ b/src/main/java/net/minecraft/world/level/Level.java
@@ -488,7 +488,7 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
                 // CraftBukkit start
                 iblockdata1.updateIndirectNeighbourShapes(this, blockposition, k, j - 1); // Don't call an event for the old block to limit event spam
                 CraftWorld world = ((ServerLevel) this).getWorld();
-                if (world != null) {
+                if (world != null && ((ServerLevel)this).hasPhysicsEvent) { // Paper
                     BlockPhysicsEvent event = new BlockPhysicsEvent(world.getBlockAt(blockposition.getX(), blockposition.getY(), blockposition.getZ()), CraftBlockData.fromData(iblockdata));
                     this.getCraftServer().getPluginManager().callEvent(event);
 
diff --git a/src/main/java/net/minecraft/world/level/block/BushBlock.java b/src/main/java/net/minecraft/world/level/block/BushBlock.java
index d40e791529911ca81398ac267a819415da91502a..03fde6e47c4a347c62fe9b4a3351769aedf874f6 100644
--- a/src/main/java/net/minecraft/world/level/block/BushBlock.java
+++ b/src/main/java/net/minecraft/world/level/block/BushBlock.java
@@ -24,7 +24,7 @@ public class BushBlock extends Block {
     public BlockState updateShape(BlockState state, Direction direction, BlockState neighborState, LevelAccessor world, BlockPos pos, BlockPos neighborPos) {
         // CraftBukkit start
         if (!state.canSurvive(world, pos)) {
-            if (!org.bukkit.craftbukkit.event.CraftEventFactory.callBlockPhysicsEvent(world, pos).isCancelled()) {
+            if (!(world instanceof net.minecraft.server.level.ServerLevel && ((net.minecraft.server.level.ServerLevel) world).hasPhysicsEvent) || !org.bukkit.craftbukkit.event.CraftEventFactory.callBlockPhysicsEvent(world, pos).isCancelled()) { // Paper
                 return Blocks.AIR.defaultBlockState();
             }
         }
diff --git a/src/main/java/net/minecraft/world/level/block/DoublePlantBlock.java b/src/main/java/net/minecraft/world/level/block/DoublePlantBlock.java
index a90f6cc0d8c0f6d115e59d07b1b4c9b45fe0ad1e..fa97966d39f01301a8ba976c02dc697e0a74bfb1 100644
--- a/src/main/java/net/minecraft/world/level/block/DoublePlantBlock.java
+++ b/src/main/java/net/minecraft/world/level/block/DoublePlantBlock.java
@@ -93,7 +93,7 @@ public class DoublePlantBlock extends BushBlock {
 
     protected static void preventCreativeDropFromBottomPart(Level world, BlockPos pos, BlockState state, Player player) {
         // CraftBukkit start
-        if (org.bukkit.craftbukkit.event.CraftEventFactory.callBlockPhysicsEvent(world, pos).isCancelled()) {
+        if (((net.minecraft.server.level.ServerLevel)world).hasPhysicsEvent && org.bukkit.craftbukkit.event.CraftEventFactory.callBlockPhysicsEvent(world, pos).isCancelled()) { // Paper
             return;
         }
         // CraftBukkit end