From a02f422d857b90eb20d0f02e30cf687aa16d0488 Mon Sep 17 00:00:00 2001
From: "Dylan K. Taylor" <odigiman@gmail.com>
Date: Sat, 17 Nov 2018 16:29:53 +0000
Subject: [PATCH] SubChunk: Fixed constant redefinition on worker threads when
 autoloading this happens when workers inherit constants but not classes.

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

diff --git a/src/pocketmine/level/format/SubChunk.php b/src/pocketmine/level/format/SubChunk.php
index a0c811b4f..8ee9a118e 100644
--- a/src/pocketmine/level/format/SubChunk.php
+++ b/src/pocketmine/level/format/SubChunk.php
@@ -23,7 +23,11 @@ declare(strict_types=1);
 
 namespace pocketmine\level\format;
 
-define(__NAMESPACE__ . '\ZERO_NIBBLE_ARRAY', str_repeat("\x00", 2048));
+$name = __NAMESPACE__ . '\ZERO_NIBBLE_ARRAY';
+if(!defined($name)){
+	define($name, str_repeat("\x00", 2048));
+}
+unset($name);
 
 class SubChunk implements SubChunkInterface{
 	protected $ids;