From 7fdfe947b074d39d1806772987c1c2a43e6bb609 Mon Sep 17 00:00:00 2001
From: "Dylan K. Taylor" <odigiman@gmail.com>
Date: Mon, 2 Dec 2019 20:15:22 +0000
Subject: [PATCH] inventory: fix some transactions being rejected for no good
 reason since 1.13, transactions such as interacting with creative inventory
 cause a spoof windowID 124 slot 50 action to appear which changes air -> air.
 This currently gets rejected because only cursor is mapped to ID 124, and it
 only has a single slot.

It is not clear what the purpose of 124:50 is, but this fix filters out any actions which do not change anything, since they won't affect transaction balance anyway.
---
 .../network/mcpe/protocol/types/NetworkInventoryAction.php    | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/pocketmine/network/mcpe/protocol/types/NetworkInventoryAction.php b/src/pocketmine/network/mcpe/protocol/types/NetworkInventoryAction.php
index abe15d8b8..ecd9eff5d 100644
--- a/src/pocketmine/network/mcpe/protocol/types/NetworkInventoryAction.php
+++ b/src/pocketmine/network/mcpe/protocol/types/NetworkInventoryAction.php
@@ -167,6 +167,10 @@ class NetworkInventoryAction{
 	 * @throws \UnexpectedValueException
 	 */
 	public function createInventoryAction(Player $player){
+		if($this->oldItem->equalsExact($this->newItem)){
+			//filter out useless noise in 1.13
+			return null;
+		}
 		switch($this->sourceType){
 			case self::SOURCE_CONTAINER:
 				$window = $player->getWindow($this->windowId);