From 4c9bf34bf3f7954313dd6e5f8d8b208119c115ca Mon Sep 17 00:00:00 2001
From: bloodshot <jdroque@gmail.com>
Date: Mon, 6 Jan 2014 18:02:01 -0500
Subject: [PATCH] Update client stack when block place is cancelled. Fixes
 BUKKIT-5284

Currently, whenever a player places a block in a protected area the
equipped itemstack size on client is never updated properly since the
client thinks the block was placed. The reason this happens is because
ItemStack.matches returns true since the server does not decrement stack
size if a BlockPlaceEvent is cancelled. To correct this on cancel we set
the flag to always update the client regardless of matching.
---
 src/main/java/net/minecraft/server/PlayerConnection.java | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/main/java/net/minecraft/server/PlayerConnection.java b/src/main/java/net/minecraft/server/PlayerConnection.java
index 9fa307ef59..75a5cbe261 100644
--- a/src/main/java/net/minecraft/server/PlayerConnection.java
+++ b/src/main/java/net/minecraft/server/PlayerConnection.java
@@ -626,7 +626,9 @@ public class PlayerConnection implements PacketPlayInListener {
                 return;
             }
 
-            this.player.playerInteractManager.interact(this.player, worldserver, itemstack, i, j, k, l, packetplayinblockplace.h(), packetplayinblockplace.i(), packetplayinblockplace.j());
+            if (!this.player.playerInteractManager.interact(this.player, worldserver, itemstack, i, j, k, l, packetplayinblockplace.h(), packetplayinblockplace.i(), packetplayinblockplace.j())) {
+                always = true; // force PacketPlayOutSetSlot to be sent to client to update ItemStack count
+            }
             // CraftBukkit end
 
             flag = true;