From 37e8c8d3244cf170c9f7b4f43582982a2f83157c Mon Sep 17 00:00:00 2001
From: "Dylan K. Taylor" <odigiman@gmail.com>
Date: Thu, 22 Feb 2018 14:48:53 +0000
Subject: [PATCH] BanEntry: work around stupid bug in ext/date
 https://bugs.php.net/bug.php?id=75992

When plugins do time-limited bans and users enter stupid time values, a shitty bug in ext/date gets triggered, but only when reading the ban entries from disk. DateTime->format() is able to produce formatted strings which have more than 4 digits in the year, which are then considered invalid. This works around it by trying to parse a formatted version on the fly to ensure that it is valid.

This also cleans up and improves ban list loading and handling.
---
 src/pocketmine/permission/BanEntry.php | 76 +++++++++++++++++++-------
 src/pocketmine/permission/BanList.php  | 12 +++-
 2 files changed, 66 insertions(+), 22 deletions(-)

diff --git a/src/pocketmine/permission/BanEntry.php b/src/pocketmine/permission/BanEntry.php
index 835a9def7..44d66177c 100644
--- a/src/pocketmine/permission/BanEntry.php
+++ b/src/pocketmine/permission/BanEntry.php
@@ -56,6 +56,7 @@ class BanEntry{
 	}
 
 	public function setCreated(\DateTime $date){
+		self::validateDate($date);
 		$this->creationDate = $date;
 	}
 
@@ -78,6 +79,9 @@ class BanEntry{
 	 * @param \DateTime|null $date
 	 */
 	public function setExpires(\DateTime $date = null){
+		if($date !== null){
+			self::validateDate($date);
+		}
 		$this->expirationDate = $date;
 	}
 
@@ -110,37 +114,71 @@ class BanEntry{
 		return $str;
 	}
 
+	/**
+	 * Hacky function to validate \DateTime objects due to a bug in PHP. format() with "Y" can emit years with more than
+	 * 4 digits, but createFromFormat() with "Y" doesn't accept them if they have more than 4 digits on the year.
+	 *
+	 * @link https://bugs.php.net/bug.php?id=75992
+	 *
+	 * @param \DateTime $dateTime
+	 * @throws \RuntimeException if the argument can't be parsed from a formatted date string
+	 */
+	private static function validateDate(\DateTime $dateTime) : void{
+		self::parseDate($dateTime->format(self::$format));
+	}
+
+	/**
+	 * @param string $date
+	 *
+	 * @return \DateTime|null
+	 * @throws \RuntimeException
+	 */
+	private static function parseDate(string $date) : ?\DateTime{
+		$datetime = \DateTime::createFromFormat(self::$format, $date);
+		if(!($datetime instanceof \DateTime)){
+			throw new \RuntimeException("Error parsing date for BanEntry: " . implode(", ", \DateTime::getLastErrors()["errors"]));
+		}
+
+		return $datetime;
+	}
+
 	/**
 	 * @param string $str
 	 *
 	 * @return BanEntry|null
+	 * @throws \RuntimeException
 	 */
-	public static function fromString(string $str){
+	public static function fromString(string $str) : ?BanEntry{
 		if(strlen($str) < 2){
 			return null;
 		}else{
 			$str = explode("|", trim($str));
 			$entry = new BanEntry(trim(array_shift($str)));
-			if(count($str) > 0){
-				$datetime = \DateTime::createFromFormat(self::$format, array_shift($str));
-				if(!($datetime instanceof \DateTime)){
-					MainLogger::getLogger()->alert("Error parsing date for BanEntry for player \"" . $entry->getName() . "\", the format may be invalid!");
-					return $entry;
+			do{
+				if(empty($str)){
+					break;
 				}
-				$entry->setCreated($datetime);
-				if(count($str) > 0){
-					$entry->setSource(trim(array_shift($str)));
-					if(count($str) > 0){
-						$expire = trim(array_shift($str));
-						if(strtolower($expire) !== "forever" and strlen($expire) > 0){
-							$entry->setExpires(\DateTime::createFromFormat(self::$format, $expire));
-						}
-						if(count($str) > 0){
-							$entry->setReason(trim(array_shift($str)));
-						}
-					}
+
+				$entry->setCreated(self::parseDate(array_shift($str)));
+				if(empty($str)){
+					break;
 				}
-			}
+
+				$entry->setSource(trim(array_shift($str)));
+				if(empty($str)){
+					break;
+				}
+
+				$expire = trim(array_shift($str));
+				if(strtolower($expire) !== "forever" and strlen($expire) > 0){
+					$entry->setExpires(self::parseDate($expire));
+				}
+				if(empty($str)){
+					break;
+				}
+
+				$entry->setReason(trim(array_shift($str)));
+			}while(false);
 
 			return $entry;
 		}
diff --git a/src/pocketmine/permission/BanList.php b/src/pocketmine/permission/BanList.php
index 0540eca1c..e13be1651 100644
--- a/src/pocketmine/permission/BanList.php
+++ b/src/pocketmine/permission/BanList.php
@@ -147,9 +147,15 @@ class BanList{
 		if(is_resource($fp)){
 			while(($line = fgets($fp)) !== false){
 				if($line{0} !== "#"){
-					$entry = BanEntry::fromString($line);
-					if($entry instanceof BanEntry){
-						$this->list[$entry->getName()] = $entry;
+					try{
+						$entry = BanEntry::fromString($line);
+						if($entry instanceof BanEntry){
+							$this->list[$entry->getName()] = $entry;
+						}
+					}catch(\Throwable $e){
+						$logger = MainLogger::getLogger();
+						$logger->critical("Failed to parse ban entry from string \"$line\": " . $e->getMessage());
+						$logger->logException($e);
 					}
 				}
 			}