From b7c43797008bcee5f0d7b87a283afab0b9210edb Mon Sep 17 00:00:00 2001
From: "Dylan K. Taylor" <odigiman@gmail.com>
Date: Mon, 2 Dec 2019 19:35:55 +0000
Subject: [PATCH] StartGamePacket: fixed asymmetry in block table handling

---
 .../network/mcpe/protocol/StartGamePacket.php | 31 +++----------------
 .../protocol/types/RuntimeBlockMapping.php    | 20 +++++++++---
 2 files changed, 19 insertions(+), 32 deletions(-)

diff --git a/src/pocketmine/network/mcpe/protocol/StartGamePacket.php b/src/pocketmine/network/mcpe/protocol/StartGamePacket.php
index e1e2212c3..64084152c 100644
--- a/src/pocketmine/network/mcpe/protocol/StartGamePacket.php
+++ b/src/pocketmine/network/mcpe/protocol/StartGamePacket.php
@@ -153,7 +153,7 @@ class StartGamePacket extends DataPacket{
 	/** @var string */
 	public $multiplayerCorrelationId = ""; //TODO: this should be filled with a UUID of some sort
 
-	/** @var array|null ["name" (string), "data" (int16), "legacy_id" (int16)] */
+	/** @var ListTag|null */
 	public $blockTable = null;
 	/** @var array|null string (name) => int16 (legacyID) */
 	public $itemTable = null;
@@ -211,14 +211,8 @@ class StartGamePacket extends DataPacket{
 
 		$this->enchantmentSeed = $this->getVarInt();
 
-		$this->blockTable = [];
-		for($i = 0, $count = $this->getUnsignedVarInt(); $i < $count; ++$i){
-			$id = $this->getString();
-			$data = $this->getSignedLShort();
-			$unknown = $this->getSignedLShort();
+		$this->blockTable = (new NetworkLittleEndianNBTStream())->read($this->buffer, false, $this->offset, 512);
 
-			$this->blockTable[$i] = ["name" => $id, "data" => $data, "legacy_id" => $unknown];
-		}
 		$this->itemTable = [];
 		for($i = 0, $count = $this->getUnsignedVarInt(); $i < $count; ++$i){
 			$id = $this->getString();
@@ -286,11 +280,11 @@ class StartGamePacket extends DataPacket{
 		if($this->blockTable === null){
 			if(self::$blockTableCache === null){
 				//this is a really nasty hack, but it'll do for now
-				self::$blockTableCache = self::serializeBlockTable(RuntimeBlockMapping::getBedrockKnownStates());
+				self::$blockTableCache = (new NetworkLittleEndianNBTStream())->write(RuntimeBlockMapping::generateBlockTable());
 			}
 			$this->put(self::$blockTableCache);
 		}else{
-			$this->put(self::serializeBlockTable($this->blockTable));
+			$this->put((new NetworkLittleEndianNBTStream())->write($this->blockTable));
 		}
 		if($this->itemTable === null){
 			if(self::$itemTableCache === null){
@@ -304,23 +298,6 @@ class StartGamePacket extends DataPacket{
 		$this->putString($this->multiplayerCorrelationId);
 	}
 
-	private static function serializeBlockTable(array $table) : string{
-		$states = new ListTag();
-		foreach($table as $v){
-			$state = new CompoundTag();
-			$state->setTag(new CompoundTag("block", [
-				new StringTag("name", $v["name"]),
-				$v["states"]
-			]));
-			$state->setShort("id", $v["legacy_id"]);
-			$states->push($state);
-		}
-		$stream = new NetworkLittleEndianNBTStream();
-		$stream->writeTag($states);
-
-		return $stream->buffer;
-	}
-
 	private static function serializeItemTable(array $table) : string{
 		$stream = new NetworkBinaryStream();
 		$stream->putUnsignedVarInt(count($table));
diff --git a/src/pocketmine/network/mcpe/protocol/types/RuntimeBlockMapping.php b/src/pocketmine/network/mcpe/protocol/types/RuntimeBlockMapping.php
index ccb92e6e3..0709582c8 100644
--- a/src/pocketmine/network/mcpe/protocol/types/RuntimeBlockMapping.php
+++ b/src/pocketmine/network/mcpe/protocol/types/RuntimeBlockMapping.php
@@ -26,6 +26,8 @@ namespace pocketmine\network\mcpe\protocol\types;
 use pocketmine\block\BlockIds;
 use pocketmine\nbt\BigEndianNBTStream;
 use pocketmine\nbt\tag\CompoundTag;
+use pocketmine\nbt\tag\ListTag;
+use pocketmine\nbt\tag\StringTag;
 use pocketmine\utils\BinaryDataException;
 use function file_get_contents;
 use function getmypid;
@@ -139,11 +141,19 @@ final class RuntimeBlockMapping{
 		self::$runtimeToLegacyMap[$staticRuntimeId] = ($legacyId << 4) | $legacyMeta;
 	}
 
-	/**
-	 * @return array
-	 */
-	public static function getBedrockKnownStates() : array{
+	public static function generateBlockTable() : ListTag{
 		self::lazyInit();
-		return self::$bedrockKnownStates;
+		$states = new ListTag();
+		//TODO: this assoc array mess really doesn't make sense anymore, we can store NBT directly
+		foreach(self::$bedrockKnownStates as $v){
+			$state = new CompoundTag();
+			$state->setTag(new CompoundTag("block", [
+				new StringTag("name", $v["name"]),
+				$v["states"]
+			]));
+			$state->setShort("id", $v["legacy_id"]);
+			$states->push($state);
+		}
+		return $states;
 	}
 }