3 files changed, 121 insertions, 6 deletions
diff --git a/phpBB/common.php b/phpBB/common.php
index 38761cfadc..48bd13e80d 100644
--- a/phpBB/common.php
+++ b/phpBB/common.php
@@ -90,8 +90,14 @@ include($phpbb_root_path . 'includes/functions_compatibility.' . $phpEx);
 require($phpbb_root_path . 'includes/constants.' . $phpEx);
 require($phpbb_root_path . 'includes/utf/utf_tools.' . $phpEx);
 
-// Set PHP error handler to ours
-set_error_handler(defined('PHPBB_MSG_HANDLER') ? PHPBB_MSG_HANDLER : 'msg_handler');
+if (PHPBB_ENVIRONMENT === 'development')
+{
+	\phpbb\debug\debug::enable();
+}
+else
+{
+	set_error_handler(defined('PHPBB_MSG_HANDLER') ? PHPBB_MSG_HANDLER : 'msg_handler');
+}
 
 $phpbb_class_loader_ext = new \phpbb\class_loader('\\', "{$phpbb_root_path}ext/", $phpEx);
 $phpbb_class_loader_ext->register();
@@ -104,10 +110,17 @@ try
 }
 catch (InvalidArgumentException $e)
 {
-	trigger_error(
-		'The requested environment ' . PHPBB_ENVIRONMENT . ' is not available.',
-		E_USER_ERROR
-	);
+	if (PHPBB_ENVIRONMENT !== 'development')
+	{
+		trigger_error(
+			'The requested environment ' . PHPBB_ENVIRONMENT . ' is not available.',
+			E_USER_ERROR
+		);
+	}
+	else
+	{
+		throw $e;
+	}
 }
 
 $phpbb_class_loader->set_cache($phpbb_container->get('cache.driver'));
diff --git a/phpBB/phpbb/debug/debug.php b/phpBB/phpbb/debug/debug.php
new file mode 100644
index 0000000000..76308e9197
--- /dev/null
+++ b/phpBB/phpbb/debug/debug.php
@@ -0,0 +1,70 @@
+<?php
+/**
+*
+* This file is part of the phpBB Forum Software package.
+*
+* @copyright (c) phpBB Limited <https://www.phpbb.com>
+* @license GNU General Public License, version 2 (GPL-2.0)
+*
+* For full copyright and license information, please see
+* the docs/CREDITS.txt file.
+*
+*/
+
+namespace phpbb\debug;
+
+use Symfony\Component\Debug\BufferingLogger;
+use Symfony\Component\Debug\DebugClassLoader;
+use Symfony\Component\Debug\ExceptionHandler;
+use Symfony\Component\Filesystem\Exception\IOException;
+
+/**
+ * Registers all the debug tools.
+
+ * @see Symfony\Component\Debug\Debug
+ */
+class Debug
+{
+	private static $enabled = false;
+
+	/**
+	 * Enables the debug tools.
+	 *
+	 * This method registers an error handler and an exception handler.
+	 *
+	 * If the Symfony ClassLoader component is available, a special
+	 * class loader is also registered.
+	 *
+	 * @param int  $errorReportingLevel The level of error reporting you want
+	 * @param bool $displayErrors       Whether to display errors (for development) or just log them (for production)
+	 */
+	public static function enable($errorReportingLevel = null, $displayErrors = true)
+	{
+		if (static::$enabled) {
+			return;
+		}
+
+		static::$enabled = true;
+
+		if (null !== $errorReportingLevel) {
+			error_reporting($errorReportingLevel);
+		} else {
+			error_reporting(-1);
+		}
+
+		if ('cli' !== php_sapi_name()) {
+			ini_set('display_errors', 0);
+			ExceptionHandler::register();
+		} elseif ($displayErrors && (!ini_get('log_errors') || ini_get('error_log'))) {
+			// CLI - display errors only if they're not already logged to STDERR
+			ini_set('display_errors', 1);
+		}
+		if ($displayErrors) {
+			error_handler::register(new error_handler(new BufferingLogger()));
+		} else {
+			error_handler::register()->throwAt(0, true);
+		}
+
+		DebugClassLoader::enable();
+	}
+}
diff --git a/phpBB/phpbb/debug/error_handler.php b/phpBB/phpbb/debug/error_handler.php
new file mode 100644
index 0000000000..2b182628a8
--- /dev/null
+++ b/phpBB/phpbb/debug/error_handler.php
@@ -0,0 +1,32 @@
+<?php
+/**
+*
+* This file is part of the phpBB Forum Software package.
+*
+* @copyright (c) phpBB Limited <https://www.phpbb.com>
+* @license GNU General Public License, version 2 (GPL-2.0)
+*
+* For full copyright and license information, please see
+* the docs/CREDITS.txt file.
+*
+*/
+
+namespace phpbb\debug;
+
+use Symfony\Component\Debug\ErrorHandler;
+use Symfony\Component\Filesystem\Exception\IOException;
+
+class error_handler extends ErrorHandler
+{
+	public function handleError($type, $message, $file, $line, array $context, array $backtrace = null)
+	{
+		if ($type === E_USER_WARNING|| $type === E_USER_NOTICE)
+		{
+			$handler = defined('PHPBB_MSG_HANDLER') ? PHPBB_MSG_HANDLER : 'msg_handler';
+
+			$handler($type, $message, $file, $line);
+		}
+
+		return parent::handleError($type, $message, $file, $line, $context, $backtrace);
+	}
+}