From 5520641b69e980691db06799793a50b52fd497ca Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Wed, 6 Feb 2019 00:20:33 -0500
Subject: [PATCH] BlockDestroyEvent

Adds an event for when the server is going to destroy a current block,
potentially causing it to drop. This event can be cancelled to avoid
the block destruction, such as preventing signs from popping when
floating in the air.

This can replace many uses of BlockPhysicsEvent

diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
index e8f83627c..61a3ddc4d 100644
--- a/src/main/java/net/minecraft/server/World.java
+++ b/src/main/java/net/minecraft/server/World.java
@@ -456,8 +456,20 @@ public abstract class World implements GeneratorAccess, AutoCloseable {
             return false;
         } else {
             Fluid fluid = this.getFluid(blockposition);
+            // Paper start - while the above setAir method is named same and looks very similar
+            // they are NOT used with same intent and the above should not fire this event. The above method is more of a BlockSetToAirEvent,
+            // it doesn't imply destruction of a block that plays a sound effect / drops an item.
+            boolean playEffect = true;
+            if (com.destroystokyo.paper.event.block.BlockDestroyEvent.getHandlerList().getRegisteredListeners().length > 0) {
+                com.destroystokyo.paper.event.block.BlockDestroyEvent event = new com.destroystokyo.paper.event.block.BlockDestroyEvent(MCUtil.toBukkitBlock(this, blockposition), fluid.getBlockData().createCraftBlockData(), flag);
+                if (!event.callEvent()) {
+                    return false;
+                }
+                playEffect = event.playEffect();
+            }
+            // Paper end
 
-            this.triggerEffect(2001, blockposition, Block.getCombinedId(iblockdata));
+            if (playEffect) this.triggerEffect(2001, blockposition, Block.getCombinedId(iblockdata)); // Paper
             if (flag) {
                 TileEntity tileentity = iblockdata.getBlock().isTileEntity() ? this.getTileEntity(blockposition) : null;
 
-- 
2.24.1