From 5842c912a9632ec877f8417b7f9cd5e82018f39d Mon Sep 17 00:00:00 2001
From: rxu <rxu@mail.ru>
Date: Wed, 18 Mar 2020 23:11:42 +0700
Subject: [PATCH] [ticket/13426] Improve user timezone initialization

PHPBB3-13426
---
 phpBB/phpbb/user.php | 46 ++++++++++++++++++++++++++++++++------------
 1 file changed, 34 insertions(+), 12 deletions(-)

diff --git a/phpBB/phpbb/user.php b/phpBB/phpbb/user.php
index 096e6d42c1..e8ec5849fd 100644
--- a/phpBB/phpbb/user.php
+++ b/phpBB/phpbb/user.php
@@ -227,15 +227,7 @@ class user extends \phpbb\session
 
 		$this->language->set_user_language($user_lang_name);
 
-		try
-		{
-			$this->timezone = new \DateTimeZone($user_timezone);
-		}
-		catch (\Exception $e)
-		{
-			// If the timezone the user has selected is invalid, we fall back to UTC.
-			$this->timezone = new \DateTimeZone('UTC');
-		}
+		$this->create_timezone($user_timezone);
 
 		$this->add_lang($lang_set);
 		unset($lang_set);
@@ -635,7 +627,7 @@ class user extends \phpbb\session
 		if (!$format_date_override)
 		{
 			$time = new $this->datetime($this, '@' . (int) $gmepoch, $utc);
-			$time->setTimezone($this->timezone);
+			$time->setTimezone($this->create_timezone());
 
 			return $time->format($format, $forcedate);
 		}
@@ -645,6 +637,36 @@ class user extends \phpbb\session
 		}
 	}
 
+	/**
+	 * Create a DateTimeZone object in the context of the current user
+	 *
+	 * @param string $user_timezone Time zone of the current user.
+	 * @return DateTimeZone DateTimeZone object linked to the current users locale
+	 */
+	public function create_timezone($user_timezone = null)
+	{
+		if (!$this->timezone)
+		{
+			if (!$user_timezone)
+			{
+				global $config;
+				$user_timezone = ($this->data['user_id'] != ANONYMOUS) ? $this->data['user_timezone'] : $config['board_timezone'];
+			}
+
+			try
+			{
+				$this->timezone = new \DateTimeZone($user_timezone);
+			}
+			catch (\Exception $e)
+			{
+				// If the timezone the user has selected is invalid, we fall back to UTC.
+				$this->timezone = new \DateTimeZone('UTC');
+			}
+		}
+
+		return $this->timezone;
+	}
+
 	/**
 	* Create a \phpbb\datetime object in the context of the current user
 	*
@@ -655,7 +677,7 @@ class user extends \phpbb\session
 	*/
 	public function create_datetime($time = 'now', \DateTimeZone $timezone = null)
 	{
-		$timezone = $timezone ?: $this->timezone;
+		$timezone = $timezone ?: $this->create_timezone();
 		return new $this->datetime($this, $time, $timezone);
 	}
 
@@ -669,7 +691,7 @@ class user extends \phpbb\session
 	*/
 	public function get_timestamp_from_format($format, $time, \DateTimeZone $timezone = null)
 	{
-		$timezone = $timezone ?: $this->timezone;
+		$timezone = $timezone ?: $this->create_timezone();
 		$date = \DateTime::createFromFormat($format, $time, $timezone);
 		return ($date !== false) ? $date->format('U') : false;
 	}