From 8480ee82eabec0ae4009d5049f7e471e5fda82df Mon Sep 17 00:00:00 2001
From: "Dylan K. Taylor" <odigiman@gmail.com>
Date: Sat, 27 Jun 2020 18:34:39 +0100
Subject: [PATCH] Player: track hardcoded window state, fixes crashes opening
 inventory on high-latency connections

---
 src/pocketmine/Player.php              | 18 +++++++++++++++---
 src/pocketmine/block/CraftingTable.php | 22 +++++++++++++---------
 2 files changed, 28 insertions(+), 12 deletions(-)

diff --git a/src/pocketmine/Player.php b/src/pocketmine/Player.php
index 1f60f3717..4cea73907 100644
--- a/src/pocketmine/Player.php
+++ b/src/pocketmine/Player.php
@@ -176,6 +176,7 @@ use pocketmine\timings\Timings;
 use pocketmine\utils\TextFormat;
 use pocketmine\utils\UUID;
 use function abs;
+use function array_key_exists;
 use function array_merge;
 use function array_values;
 use function assert;
@@ -315,6 +316,15 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 	/** @var CraftingTransaction|null */
 	protected $craftingTransaction = null;
 
+	/**
+	 * TODO: HACK! This tracks GUIs for inventories that the server considers "always open" so that the client can't
+	 * open them twice. (1.16 hack)
+	 * @var true[]
+	 * @phpstan-var array<int, true>
+	 * @internal
+	 */
+	public $openHardcodedWindows = [];
+
 	/** @var int */
 	protected $messageCounter = 2;
 	/** @var bool */
@@ -2795,12 +2805,13 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 			case InteractPacket::ACTION_MOUSEOVER:
 				break; //TODO: handle these
 			case InteractPacket::ACTION_OPEN_INVENTORY:
-				if($target === $this){
+				if($target === $this && !array_key_exists($windowId = self::HARDCODED_INVENTORY_WINDOW_ID, $this->openHardcodedWindows)){
 					//TODO: HACK! this restores 1.14ish behaviour, but this should be able to be listened to and
 					//controlled by plugins. However, the player is always a subscriber to their own inventory so it
 					//doesn't integrate well with the regular container system right now.
+					$this->openHardcodedWindows[$windowId] = true;
 					$pk = new ContainerOpenPacket();
-					$pk->windowId = self::HARDCODED_INVENTORY_WINDOW_ID;
+					$pk->windowId = $windowId;
 					$pk->type = WindowTypes::INVENTORY;
 					$pk->x = $pk->y = $pk->z = 0;
 					$pk->entityUniqueId = $this->getId();
@@ -3027,7 +3038,8 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 
 		$this->doCloseInventory();
 
-		if($packet->windowId >= self::RESERVED_WINDOW_ID_RANGE_START and $packet->windowId <= self::RESERVED_WINDOW_ID_RANGE_END){
+		if(array_key_exists($packet->windowId, $this->openHardcodedWindows)){
+			unset($this->openHardcodedWindows[$packet->windowId]);
 			$pk = new ContainerClosePacket();
 			$pk->windowId = $packet->windowId;
 			$this->sendDataPacket($pk);
diff --git a/src/pocketmine/block/CraftingTable.php b/src/pocketmine/block/CraftingTable.php
index bb2fe5c39..0d898384c 100644
--- a/src/pocketmine/block/CraftingTable.php
+++ b/src/pocketmine/block/CraftingTable.php
@@ -28,6 +28,7 @@ use pocketmine\item\Item;
 use pocketmine\network\mcpe\protocol\ContainerOpenPacket;
 use pocketmine\network\mcpe\protocol\types\WindowTypes;
 use pocketmine\Player;
+use function array_key_exists;
 
 class CraftingTable extends Solid{
 
@@ -53,15 +54,18 @@ class CraftingTable extends Solid{
 		if($player instanceof Player){
 			$player->setCraftingGrid(new CraftingGrid($player, CraftingGrid::SIZE_BIG));
 
-			//TODO: HACK! crafting grid doesn't fit very well into the current PM container system, so this hack allows
-			//it to carry on working approximately the same way as it did in 1.14
-			$pk = new ContainerOpenPacket();
-			$pk->windowId = Player::HARDCODED_CRAFTING_GRID_WINDOW_ID;
-			$pk->type = WindowTypes::WORKBENCH;
-			$pk->x = $this->getFloorX();
-			$pk->y = $this->getFloorY();
-			$pk->z = $this->getFloorZ();
-			$player->sendDataPacket($pk);
+			if(!array_key_exists($windowId = Player::HARDCODED_CRAFTING_GRID_WINDOW_ID, $player->openHardcodedWindows)){
+				//TODO: HACK! crafting grid doesn't fit very well into the current PM container system, so this hack allows
+				//it to carry on working approximately the same way as it did in 1.14
+				$pk = new ContainerOpenPacket();
+				$pk->windowId = $windowId;
+				$pk->type = WindowTypes::WORKBENCH;
+				$pk->x = $this->getFloorX();
+				$pk->y = $this->getFloorY();
+				$pk->z = $this->getFloorZ();
+				$player->sendDataPacket($pk);
+				$player->openHardcodedWindows[$windowId] = true;
+			}
 		}
 
 		return true;