From 5a54d098690d1c46a3dd56382928c75426c055cd Mon Sep 17 00:00:00 2001
From: "Dylan K. Taylor" <dktapps@pmmp.io>
Date: Thu, 27 Apr 2023 13:18:28 +0100
Subject: [PATCH] InventoryManager: verify slot existence in
 locateWindowAndSlot()

previously, this would happily return invalid slot IDs, potentially leading to a crash.
---
 src/network/mcpe/InventoryManager.php | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/network/mcpe/InventoryManager.php b/src/network/mcpe/InventoryManager.php
index a651b9213..c6d83c65e 100644
--- a/src/network/mcpe/InventoryManager.php
+++ b/src/network/mcpe/InventoryManager.php
@@ -205,11 +205,13 @@ class InventoryManager{
 			if($entry === null){
 				return null;
 			}
+			$inventory = $entry->getInventory();
 			$coreSlotId = $entry->mapNetToCore($netSlotId);
-			return $coreSlotId !== null ? [$entry->getInventory(), $coreSlotId] : null;
+			return $coreSlotId !== null && $inventory->slotExists($coreSlotId) ? [$inventory, $coreSlotId] : null;
 		}
-		if(isset($this->networkIdToInventoryMap[$windowId])){
-			return [$this->networkIdToInventoryMap[$windowId], $netSlotId];
+		$inventory = $this->networkIdToInventoryMap[$windowId] ?? null;
+		if($inventory !== null && $inventory->slotExists($netSlotId)){
+			return [$inventory, $netSlotId];
 		}
 		return null;
 	}