From e6a58e269099a7942d157a214beacc6c30f5617d Mon Sep 17 00:00:00 2001
From: "Dylan K. Taylor" <odigiman@gmail.com>
Date: Wed, 8 Jan 2020 09:55:03 +0000
Subject: [PATCH] format/leveldb: fix crash on truncated level.dat file

---
 src/pocketmine/level/format/io/leveldb/LevelDB.php | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/pocketmine/level/format/io/leveldb/LevelDB.php b/src/pocketmine/level/format/io/leveldb/LevelDB.php
index 30b8d7bdea..1a355062db 100644
--- a/src/pocketmine/level/format/io/leveldb/LevelDB.php
+++ b/src/pocketmine/level/format/io/leveldb/LevelDB.php
@@ -126,8 +126,12 @@ class LevelDB extends BaseLevelProvider{
 	}
 
 	protected function loadLevelData() : void{
+		$rawLevelData = file_get_contents($this->getPath() . "level.dat");
+		if($rawLevelData === false or strlen($rawLevelData) <= 8){
+			throw new LevelException("Truncated level.dat");
+		}
 		$nbt = new LittleEndianNBTStream();
-		$levelData = $nbt->read(substr(file_get_contents($this->getPath() . "level.dat"), 8));
+		$levelData = $nbt->read(substr($rawLevelData, 8));
 		if($levelData instanceof CompoundTag){
 			$this->levelData = $levelData;
 		}else{