From b66095cb36b24ccd0ce8ace1b2448cc3f9de7c9d Mon Sep 17 00:00:00 2001
From: "Dylan K. Taylor" <odigiman@gmail.com>
Date: Sun, 19 Aug 2018 10:10:40 +0100
Subject: [PATCH 1/2] Added a hack for MC W10 JSON empty strings bug (#2383)

---
 .../mcpe/PlayerNetworkSessionAdapter.php      | 32 ++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/src/pocketmine/network/mcpe/PlayerNetworkSessionAdapter.php b/src/pocketmine/network/mcpe/PlayerNetworkSessionAdapter.php
index b8801815fe..d405905cc2 100644
--- a/src/pocketmine/network/mcpe/PlayerNetworkSessionAdapter.php
+++ b/src/pocketmine/network/mcpe/PlayerNetworkSessionAdapter.php
@@ -239,7 +239,37 @@ class PlayerNetworkSessionAdapter extends NetworkSession{
 	}
 
 	public function handleModalFormResponse(ModalFormResponsePacket $packet) : bool{
-		return $this->player->onFormSubmit($packet->formId, json_decode($packet->formData, true));
+		return $this->player->onFormSubmit($packet->formId, self::stupid_json_decode($packet->formData, true));
+	}
+
+	/**
+	 * Hack to work around a stupid bug in Minecraft W10 which causes empty strings to be sent unquoted in form responses.
+	 *
+	 * @param string $json
+	 * @param bool   $assoc
+	 *
+	 * @return mixed
+	 */
+	private static function stupid_json_decode(string $json, bool $assoc = false){
+		if(preg_match('/^\[(.+)\]$/s', $json, $matches) > 0){
+			$parts = preg_split('/(?:"(?:\\"|[^"])*"|)\K(,)/', $matches[1]); //Splits on commas not inside quotes, ignoring escaped quotes
+			foreach($parts as $k => $part){
+				$part = trim($part);
+				if($part === ""){
+					$part = "\"\"";
+				}
+				$parts[$k] = $part;
+			}
+
+			$fixed = "[" . implode(",", $parts) . "]";
+			if(($ret = json_decode($fixed, $assoc)) === null){
+				throw new \InvalidArgumentException("Failed to fix JSON: " . json_last_error_msg() . "(original: $json, modified: $fixed)");
+			}
+
+			return $ret;
+		}
+
+		return json_decode($json, $assoc);
 	}
 
 	public function handleServerSettingsRequest(ServerSettingsRequestPacket $packet) : bool{

From bfa415e1089b30b6f7686ea325108a6b7cf08958 Mon Sep 17 00:00:00 2001
From: "Dylan K. Taylor" <odigiman@gmail.com>
Date: Sun, 19 Aug 2018 10:30:52 +0100
Subject: [PATCH 2/2] Add unit tests for json decoding hack

---
 .../network/mcpe/StupidJsonDecodeTest.php     | 56 +++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 tests/phpunit/network/mcpe/StupidJsonDecodeTest.php

diff --git a/tests/phpunit/network/mcpe/StupidJsonDecodeTest.php b/tests/phpunit/network/mcpe/StupidJsonDecodeTest.php
new file mode 100644
index 0000000000..b096c6c9d7
--- /dev/null
+++ b/tests/phpunit/network/mcpe/StupidJsonDecodeTest.php
@@ -0,0 +1,56 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+*/
+
+declare(strict_types=1);
+
+namespace pocketmine\network\mcpe;
+
+use PHPUnit\Framework\TestCase;
+
+class StupidJsonDecodeTest extends TestCase{
+
+	public function stupidJsonDecodeProvider() : array{
+		return [
+			["[\n   \"a\",\"b,c,d,e\\\"   \",,0,1,2, false, 0.001]", ['a', 'b,c,d,e"   ', '', 0, 1, 2, false, 0.001]],
+			["0", 0],
+			["false", false],
+			["NULL", null],
+			['["\",,\"word","a\",,\"word2",]', ['",,"word', 'a",,"word2', '']],
+			['["\",,\"word","a\",,\"word2",""]', ['",,"word', 'a",,"word2', '']]
+		];
+	}
+
+	/**
+	 * @dataProvider stupidJsonDecodeProvider
+	 *
+	 * @param string $brokenJson
+	 * @param mixed  $expect
+	 *
+	 * @throws \ReflectionException
+	 */
+	public function testStupidJsonDecode(string $brokenJson, $expect){
+		$func = new \ReflectionMethod(PlayerNetworkSessionAdapter::class, 'stupid_json_decode');
+		$func->setAccessible(true);
+
+		$decoded = $func->invoke(null, $brokenJson, true);
+		self::assertEquals($expect, $decoded);
+	}
+}