From 465285b3c2a51c18f47a6db9db8d7bc73a741dab Mon Sep 17 00:00:00 2001
From: "Dylan K. Taylor" <odigiman@gmail.com>
Date: Sat, 13 Jun 2020 12:26:17 +0100
Subject: [PATCH] do not rely on GameMode::getMagicNumber() to match protocol
 IDs

---
 src/network/mcpe/NetworkSession.php            |  2 +-
 src/network/mcpe/convert/TypeConverter.php     | 18 +++++++++++++++++-
 .../mcpe/handler/InGamePacketHandler.php       |  3 ++-
 .../mcpe/handler/PreSpawnPacketHandler.php     |  4 ++--
 4 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/src/network/mcpe/NetworkSession.php b/src/network/mcpe/NetworkSession.php
index cf449bf52..d53d1d86f 100644
--- a/src/network/mcpe/NetworkSession.php
+++ b/src/network/mcpe/NetworkSession.php
@@ -684,7 +684,7 @@ class NetworkSession{
 	}
 
 	public function syncGameMode(GameMode $mode, bool $isRollback = false) : void{
-		$this->sendDataPacket(SetPlayerGameTypePacket::create(TypeConverter::getInstance()->getClientFriendlyGamemode($mode)));
+		$this->sendDataPacket(SetPlayerGameTypePacket::create(TypeConverter::getInstance()->coreGameModeToProtocol($mode)));
 		$this->syncAdventureSettings($this->player);
 		if(!$isRollback){
 			$this->invManager->syncCreative();
diff --git a/src/network/mcpe/convert/TypeConverter.php b/src/network/mcpe/convert/TypeConverter.php
index cd0bc83c9..b421fc8c9 100644
--- a/src/network/mcpe/convert/TypeConverter.php
+++ b/src/network/mcpe/convert/TypeConverter.php
@@ -56,7 +56,7 @@ class TypeConverter{
 	 *
 	 * @internal
 	 */
-	public function getClientFriendlyGamemode(GameMode $gamemode) : int{
+	public function coreGameModeToProtocol(GameMode $gamemode) : int{
 		switch($gamemode->id()){
 			case GameMode::SURVIVAL()->id():
 				return ProtocolGameMode::SURVIVAL;
@@ -70,6 +70,22 @@ class TypeConverter{
 		}
 	}
 
+	public function protocolGameModeToCore(int $gameMode) : GameMode{
+		switch($gameMode){
+			case ProtocolGameMode::SURVIVAL:
+				return GameMode::SURVIVAL();
+			case ProtocolGameMode::CREATIVE:
+				return GameMode::CREATIVE();
+			case ProtocolGameMode::ADVENTURE:
+				return GameMode::ADVENTURE();
+			case ProtocolGameMode::CREATIVE_VIEWER:
+			case ProtocolGameMode::SURVIVAL_VIEWER:
+				return GameMode::SPECTATOR();
+			default:
+				throw new \UnexpectedValueException("Unmapped protocol game mode $gameMode");
+		}
+	}
+
 	public function coreItemStackToRecipeIngredient(Item $itemStack) : RecipeIngredient{
 		$meta = $itemStack->getMeta();
 		return new RecipeIngredient($itemStack->getId(), $meta === -1 ? 0x7fff : $meta, $itemStack->getCount());
diff --git a/src/network/mcpe/handler/InGamePacketHandler.php b/src/network/mcpe/handler/InGamePacketHandler.php
index 8afb331f8..e5041ab19 100644
--- a/src/network/mcpe/handler/InGamePacketHandler.php
+++ b/src/network/mcpe/handler/InGamePacketHandler.php
@@ -582,7 +582,8 @@ class InGamePacketHandler extends PacketHandler{
 	}
 
 	public function handleSetPlayerGameType(SetPlayerGameTypePacket $packet) : bool{
-		if($packet->gamemode !== $this->player->getGamemode()->getMagicNumber()){
+		$converter = TypeConverter::getInstance();
+		if(!$converter->protocolGameModeToCore($packet->gamemode)->equals($this->player->getGamemode())){
 			//Set this back to default. TODO: handle this properly
 			$this->session->syncGameMode($this->player->getGamemode(), true);
 		}
diff --git a/src/network/mcpe/handler/PreSpawnPacketHandler.php b/src/network/mcpe/handler/PreSpawnPacketHandler.php
index b681b3171..007da0fb7 100644
--- a/src/network/mcpe/handler/PreSpawnPacketHandler.php
+++ b/src/network/mcpe/handler/PreSpawnPacketHandler.php
@@ -59,13 +59,13 @@ class PreSpawnPacketHandler extends PacketHandler{
 		$pk = new StartGamePacket();
 		$pk->entityUniqueId = $this->player->getId();
 		$pk->entityRuntimeId = $this->player->getId();
-		$pk->playerGamemode = TypeConverter::getInstance()->getClientFriendlyGamemode($this->player->getGamemode());
+		$pk->playerGamemode = TypeConverter::getInstance()->coreGameModeToProtocol($this->player->getGamemode());
 		$pk->playerPosition = $this->player->getOffsetPosition($location);
 		$pk->pitch = $location->pitch;
 		$pk->yaw = $location->yaw;
 		$pk->seed = -1;
 		$pk->dimension = DimensionIds::OVERWORLD; //TODO: implement this properly
-		$pk->worldGamemode = TypeConverter::getInstance()->getClientFriendlyGamemode($this->server->getGamemode());
+		$pk->worldGamemode = TypeConverter::getInstance()->coreGameModeToProtocol($this->server->getGamemode());
 		$pk->difficulty = $location->getWorldNonNull()->getDifficulty();
 		$pk->spawnX = $spawnPosition->getFloorX();
 		$pk->spawnY = $spawnPosition->getFloorY();