From 2330f363bd15a2c953fd538a807aba819405204f Mon Sep 17 00:00:00 2001
From: Shoghi Cervantes <shoghicp@gmail.com>
Date: Sun, 27 Jul 2014 20:54:28 +0200
Subject: [PATCH] Fix for thrown EmptyChunkSection modification exception

---
 src/pocketmine/level/format/LevelProvider.php |  7 ++++
 src/pocketmine/level/format/anvil/Anvil.php   | 10 ++++++
 .../level/format/generic/BaseChunk.php        | 35 ++++++++++++++++---
 3 files changed, 47 insertions(+), 5 deletions(-)

diff --git a/src/pocketmine/level/format/LevelProvider.php b/src/pocketmine/level/format/LevelProvider.php
index fae814185..ea7b70f62 100644
--- a/src/pocketmine/level/format/LevelProvider.php
+++ b/src/pocketmine/level/format/LevelProvider.php
@@ -80,6 +80,13 @@ interface LevelProvider{
 	 */
 	public function getChunk($X, $Z, $create = false);
 
+	/**
+	 * @param $Y 0-7
+	 *
+	 * @return ChunkSection
+	 */
+	public function createChunkSection($Y);
+
 	public function saveChunks();
 
 	/**
diff --git a/src/pocketmine/level/format/anvil/Anvil.php b/src/pocketmine/level/format/anvil/Anvil.php
index 9754d2a38..60dbe8ad6 100644
--- a/src/pocketmine/level/format/anvil/Anvil.php
+++ b/src/pocketmine/level/format/anvil/Anvil.php
@@ -223,6 +223,16 @@ class Anvil extends BaseLevelProvider{
 		}
 	}
 
+	public function createChunkSection($Y){
+		return new ChunkSection(new Compound(null, [
+			"Y" => new Byte("Y", $Y),
+			"Blocks" => new ByteArray("Blocks", str_repeat("\xff", 4096)),
+			"Data" => new ByteArray("Data", str_repeat("\xff", 2048)),
+			"SkyLight" => new ByteArray("SkyLight", str_repeat("\xff", 2048)), //TODO
+			"BlockLight" => new ByteArray("BlockLight", str_repeat("\x00", 2048)) //TODO
+		]));
+	}
+
 	public function isChunkGenerated($chunkX, $chunkZ){
 		if(($region = $this->getRegion($chunkX >> 5, $chunkZ >> 5)) instanceof RegionLoader){
 			return $region->chunkExists($chunkX - $region->getX() * 32, $chunkZ - $region->getZ() * 32);
diff --git a/src/pocketmine/level/format/generic/BaseChunk.php b/src/pocketmine/level/format/generic/BaseChunk.php
index ef1394465..561eb1c79 100644
--- a/src/pocketmine/level/format/generic/BaseChunk.php
+++ b/src/pocketmine/level/format/generic/BaseChunk.php
@@ -160,7 +160,12 @@ abstract class BaseChunk implements Chunk{
 	}
 
 	public function setBlock($x, $y, $z, $blockId = null, $meta = null){
-		return $this->sections[$y >> 4]->setBlock($x, $y & 0x0f, $z, $blockId & 0xff, $meta & 0x0f);
+		try{
+			return $this->sections[$y >> 4]->setBlock($x, $y & 0x0f, $z, $blockId & 0xff, $meta & 0x0f);
+		}catch(\Exception $e){
+			$this->setSection($Y = $y >> 4, $this->getLevel()->createChunkSection($Y));
+			return $this->setBlock($x, $y, $z, $blockId, $meta);
+		}
 	}
 
 	public function getBlockId($x, $y, $z){
@@ -168,7 +173,12 @@ abstract class BaseChunk implements Chunk{
 	}
 
 	public function setBlockId($x, $y, $z, $id){
-		$this->sections[$y >> 4]->setBlockId($x, $y & 0x0f, $z, $id);
+		try{
+			$this->sections[$y >> 4]->setBlockId($x, $y & 0x0f, $z, $id);
+		}catch(\Exception $e){
+			$this->setSection($Y = $y >> 4, $this->getLevel()->createChunkSection($Y));
+			$this->setBlockId($x, $y, $z, $id);
+		}
 	}
 
 	public function getBlockData($x, $y, $z){
@@ -176,7 +186,12 @@ abstract class BaseChunk implements Chunk{
 	}
 
 	public function setBlockData($x, $y, $z, $data){
-		$this->sections[$y >> 4]->setBlockData($x, $y & 0x0f, $z, $data);
+		try{
+			$this->sections[$y >> 4]->setBlockData($x, $y & 0x0f, $z, $data);
+		}catch(\Exception $e){
+			$this->setSection($Y = $y >> 4, $this->getLevel()->createChunkSection($Y));
+			$this->setBlockData($x, $y, $z, $data);
+		}
 	}
 
 	public function getBlockSkyLight($x, $y, $z){
@@ -184,7 +199,12 @@ abstract class BaseChunk implements Chunk{
 	}
 
 	public function setBlockSkyLight($x, $y, $z, $data){
-		$this->sections[$y >> 4]->getBlockSkyLight($x, $y & 0x0f, $z, $data);
+		try{
+			$this->sections[$y >> 4]->getBlockSkyLight($x, $y & 0x0f, $z, $data);
+		}catch(\Exception $e){
+			$this->setSection($Y = $y >> 4, $this->getLevel()->createChunkSection($Y));
+			$this->setBlockSkyLight($x, $y, $z, $data);
+		}
 	}
 
 	public function getBlockLight($x, $y, $z){
@@ -192,7 +212,12 @@ abstract class BaseChunk implements Chunk{
 	}
 
 	public function setBlockLight($x, $y, $z, $data){
-		$this->sections[$y >> 4]->getBlockSkyLight($x, $y & 0x0f, $z, $data);
+		try{
+			$this->sections[$y >> 4]->getBlockSkyLight($x, $y & 0x0f, $z, $data);
+		}catch(\Exception $e){
+			$this->setSection($Y = $y >> 4, $this->getLevel()->createChunkSection($Y));
+			$this->setBlockLight($x, $y, $z, $data);
+		}
 	}
 
 	public function getBiomeId($x, $z){