updateSettingsFile()

Complexity

Conditions	210
Paths	> 20000

Size

Total Lines	1390
Code Lines	798

Duplication

Lines	0
Ratio	0 %

Importance

Changes	7
Bugs	0	Features	0

<?php
function updateSettingsFile($config_vars, $keep_quotes = null, $rebuild = false)
{
	// In this function we intentionally don't declare any global variables.
	// This allows us to work with everything cleanly.

	static $mtime;

	// Should we try to unescape the strings?
	if (empty($keep_quotes))
	{
		foreach ($config_vars as $var => $val)
		{
			if (is_string($val) && ($keep_quotes === false || strpos($val, '\'') === 0 && strrpos($val, '\'') === strlen($val) - 1))
				$config_vars[$var] = trim(stripcslashes($val), '\'');
		}
	}

	// Updating the db_last_error, then don't mess around with Settings.php
	if (isset($config_vars['db_last_error']))
	{
		updateDbLastError($config_vars['db_last_error']);

		if (count($config_vars) === 1 && empty($rebuild))
			return true;

		// Make sure we delete this from Settings.php, if present.
		$config_vars['db_last_error'] = 0;
	}

	// Rebuilding should not be undertaken lightly, so we're picky about the parameter.
	if (!is_bool($rebuild))

The condition is_bool($rebuild) is always true.

		$rebuild = false;

	$mtime = isset($mtime) ? (int) $mtime : (defined('TIME_START') ? TIME_START : $_SERVER['REQUEST_TIME']);

	/*****************
	 * PART 1: Setup *
	 *****************/

	// Typically Settings.php is in $boarddir, but maybe this is a custom setup...
	foreach (get_included_files() as $settingsFile)
		if (basename($settingsFile) === 'Settings.php')
			break;

	// Fallback in case Settings.php isn't loaded (e.g. while installing)
	if (basename($settingsFile) !== 'Settings.php')

The variable $settingsFile seems to be defined by a foreach iteration on line 347. Are you sure the iterator is never empty, otherwise this variable is not defined?

		$settingsFile = (!empty($GLOBALS['boarddir']) && @realpath($GLOBALS['boarddir']) ? $GLOBALS['boarddir'] : (!empty($_SERVER['SCRIPT_FILENAME']) ? dirname($_SERVER['SCRIPT_FILENAME']) : dirname(__DIR__))) . '/Settings.php';

	// File not found? Attempt an emergency on-the-fly fix!
	if (!file_exists($settingsFile))
		@touch($settingsFile);

	// When was Settings.php last changed?
	$last_settings_change = filemtime($settingsFile);

	// Get the current values of everything in Settings.php.
	$settings_vars = get_current_settings($mtime, $settingsFile);

	// If Settings.php is empty for some reason, see if we can use the backup.
	if (empty($settings_vars) && file_exists(dirname($settingsFile) . '/Settings_bak.php'))
		$settings_vars = get_current_settings($mtime, dirname($settingsFile) . '/Settings_bak.php');

	// False means there was a problem with the file and we can't safely continue.
	if ($settings_vars === false)
		return false;

	// It works best to set everything afresh.
	$new_settings_vars = array_merge($settings_vars, $config_vars);

	// Are we using UTF-8?
	$utf8 = isset($GLOBALS['context']['utf8']) ? $GLOBALS['context']['utf8'] : (isset($GLOBALS['utf8']) ? $GLOBALS['utf8'] : (isset($settings_vars['db_character_set']) ? $settings_vars['db_character_set'] === 'utf8' : false));

The assignment to $utf8 is dead and can be removed.

	/*
	 * A big, fat array to define properties of all the Settings.php variables.
	 *
	 * - String keys are used to identify actual variables.
	 *
	 * - Integer keys are used for content not connected to any particular
	 *   variable, such as code blocks or the license block.
	 *
	 * - The content of the 'text' element is simply printed out, if it is used
	 *   at all. Use it for comments or to insert code blocks, etc.
	 *
	 * - The 'default' element, not surprisingly, gives a default value for
	 *   the variable.
	 *
	 * - The 'type' element defines the expected variable type or types. If
	 *   more than one type is allowed, this should be an array listing them.
	 *   Types should match the possible types returned by gettype().
	 *
	 * - If 'raw_default' is true, the default should be printed directly,
	 *   rather than being handled as a string. Use it if the default contains
	 *   code, e.g. 'dirname(__FILE__)'
	 *
	 * - If 'required' is true and a value for the variable is undefined,
	 *   the update will be aborted. (The only exception is during the SMF
	 *   installation process.)
	 *
	 * - If 'auto_delete' is 1 or true and the variable is empty, the variable
	 *   will be deleted from Settings.php. If 'auto_delete' is 0/false/null,
	 *   the variable will never be deleted. If 'auto_delete' is 2, behaviour
	 *   depends on $rebuild: if $rebuild is true, 'auto_delete' == 2 behaves
	 *   like 'auto_delete' == 1; if $rebuild is false, 'auto_delete' == 2
	 *   behaves like 'auto_delete' == 0.
	 *
	 * - The optional 'search_pattern' element defines a custom regular
	 *   expression to search for the existing entry in the file. This is
	 *   primarily useful for code blocks rather than variables.
	 *
	 * - The optional 'replace_pattern' element defines a custom regular
	 *   expression to decide where the replacement entry should be inserted.
	 *   Note: 'replace_pattern' should be avoided unless ABSOLUTELY necessary.
	 */
	$settings_defs = array(
		array(
			'text' => implode("\n", array(
				'',
				'/**',
				' * The settings file contains all of the basic settings that need to be present when a database/cache is not available.',
				' *',
				' * Simple Machines Forum (SMF)',
				' *',
				' * @package SMF',
				' * @author Simple Machines https://www.simplemachines.org',
				' * @copyright ' . SMF_SOFTWARE_YEAR . ' Simple Machines and individual contributors',
				' * @license https://www.simplemachines.org/about/smf/license.php BSD',
				' *',
				' * @version ' . SMF_VERSION,
				' */',
				'',
			)),
			'search_pattern' => '~/\*\*.*?@package\h+SMF\b.*?\*/\n{0,2}~s',
		),
		'maintenance' => array(
			'text' => implode("\n", array(
				'',
				'########## Maintenance ##########',
				'/**',
				' * The maintenance "mode"',
				' * Set to 1 to enable Maintenance Mode, 2 to make the forum untouchable. (you\'ll have to make it 0 again manually!)',
				' * 0 is default and disables maintenance mode.',
				' *',
				' * @var int 0, 1, 2',
				' * @global int $maintenance',
				' */',
			)),
			'default' => 0,
			'type' => 'integer',
		),
		'mtitle' => array(
			'text' => implode("\n", array(
				'/**',
				' * Title for the Maintenance Mode message.',
				' *',
				' * @var string',
				' * @global int $mtitle',
				' */',
			)),
			'default' => 'Maintenance Mode',
			'type' => 'string',
		),
		'mmessage' => array(
			'text' => implode("\n", array(
				'/**',
				' * Description of why the forum is in maintenance mode.',
				' *',
				' * @var string',
				' * @global string $mmessage',
				' */',
			)),
			'default' => 'Okay faithful users...we\'re attempting to restore an older backup of the database...news will be posted once we\'re back!',
			'type' => 'string',
		),
		'mbname' => array(
			'text' => implode("\n", array(
				'',
				'########## Forum Info ##########',
				'/**',
				' * The name of your forum.',
				' *',
				' * @var string',
				' */',
			)),
			'default' => 'My Community',
			'type' => 'string',
		),
		'language' => array(
			'text' => implode("\n", array(
				'/**',
				' * The default language file set for the forum.',
				' *',
				' * @var string',
				' */',
			)),
			'default' => 'english',
			'type' => 'string',
		),
		'boardurl' => array(
			'text' => implode("\n", array(
				'/**',
				' * URL to your forum\'s folder. (without the trailing /!)',
				' *',
				' * @var string',
				' */',
			)),
			'default' => 'http://127.0.0.1/smf',
			'type' => 'string',
		),
		'webmaster_email' => array(
			'text' => implode("\n", array(
				'/**',
				' * Email address to send emails from. (like noreply@yourdomain.com.)',
				' *',
				' * @var string',
				' */',
			)),
			'default' => 'noreply@myserver.com',
			'type' => 'string',
		),
		'cookiename' => array(
			'text' => implode("\n", array(
				'/**',
				' * Name of the cookie to set for authentication.',
				' *',
				' * @var string',
				' */',
			)),
			'default' => 'SMFCookie11',
			'type' => 'string',
		),
		'auth_secret' => array(
			'text' => implode("\n", array(
				'/**',
				' * Secret key used to create and verify cookies, tokens, etc.',
				' * Do not change this unless absolutely necessary, and NEVER share it.',
				' *',
				' * Note: Changing this will immediately log out all members of your forum',
				' * and break the token-based links in all previous email notifications,',
				' * among other possible effects.',
				' *',
				' * @var string',
				' */',
			)),
			'default' => null,
			'auto_delete' => 1,
			'type' => 'string',
		),
		'db_type' => array(
			'text' => implode("\n", array(
				'',
				'########## Database Info ##########',
				'/**',
				' * The database type',
				' * Default options: mysql, postgresql',
				' *',
				' * @var string',
				' */',
			)),
			'default' => 'mysql',
			'type' => 'string',
		),
		'db_port' => array(
			'text' => implode("\n", array(
				'/**',
				' * The database port',
				' * 0 to use default port for the database type',
				' *',
				' * @var int',
				' */',
			)),
			'default' => 0,
			'type' => 'integer',
		),
		'db_server' => array(
			'text' => implode("\n", array(
				'/**',
				' * The server to connect to (or a Unix socket)',
				' *',
				' * @var string',
				' */',
			)),
			'default' => 'localhost',
			'required' => true,
			'type' => 'string',
		),
		'db_name' => array(
			'text' => implode("\n", array(
				'/**',
				' * The database name',
				' *',
				' * @var string',
				' */',
			)),
			'default' => 'smf',
			'required' => true,
			'type' => 'string',
		),
		'db_user' => array(
			'text' => implode("\n", array(
				'/**',
				' * Database username',
				' *',
				' * @var string',
				' */',
			)),
			'default' => 'root',
			'required' => true,
			'type' => 'string',
		),
		'db_passwd' => array(
			'text' => implode("\n", array(
				'/**',
				' * Database password',
				' *',
				' * @var string',
				' */',
			)),
			'default' => '',
			'required' => true,
			'type' => 'string',
		),
		'ssi_db_user' => array(
			'text' => implode("\n", array(
				'/**',
				' * Database user for when connecting with SSI',
				' *',
				' * @var string',
				' */',
			)),
			'default' => '',
			'type' => 'string',
		),
		'ssi_db_passwd' => array(
			'text' => implode("\n", array(
				'/**',
				' * Database password for when connecting with SSI',
				' *',
				' * @var string',
				' */',
			)),
			'default' => '',
			'type' => 'string',
		),
		'db_prefix' => array(
			'text' => implode("\n", array(
				'/**',
				' * A prefix to put in front of your table names.',
				' * This helps to prevent conflicts',
				' *',
				' * @var string',
				' */',
			)),
			'default' => 'smf_',
			'required' => true,
			'type' => 'string',
		),
		'db_persist' => array(
			'text' => implode("\n", array(
				'/**',
				' * Use a persistent database connection',
				' *',
				' * @var bool',
				' */',
			)),
			'default' => false,
			'type' => 'boolean',
		),
		'db_error_send' => array(
			'text' => implode("\n", array(
				'/**',
				' * Send emails on database connection error',
				' *',
				' * @var bool',
				' */',
			)),
			'default' => false,
			'type' => 'boolean',
		),
		'db_mb4' => array(
			'text' => implode("\n", array(
				'/**',
				' * Override the default behavior of the database layer for mb4 handling',
				' * null keep the default behavior untouched',
				' *',
				' * @var null|bool',
				' */',
			)),
			'default' => null,
			'type' => array('NULL', 'boolean'),
		),
		'cache_accelerator' => array(
			'text' => implode("\n", array(
				'',
				'########## Cache Info ##########',
				'/**',
				' * Select a cache system. You want to leave this up to the cache area of the admin panel for',
				' * proper detection of apc, memcached, output_cache, smf, or xcache',
				' * (you can add more with a mod).',
				' *',
				' * @var string',
				' */',
			)),
			'default' => '',
			'type' => 'string',
		),
		'cache_enable' => array(
			'text' => implode("\n", array(
				'/**',
				' * The level at which you would like to cache. Between 0 (off) through 3 (cache a lot).',
				' *',
				' * @var int',
				' */',
			)),
			'default' => 0,
			'type' => 'integer',
		),
		'cache_memcached' => array(
			'text' => implode("\n", array(
				'/**',
				' * This is only used for memcache / memcached. Should be a string of \'server:port,server:port\'',
				' *',
				' * @var array',
				' */',
			)),
			'default' => '',
			'type' => 'string',
		),
		'cachedir' => array(
			'text' => implode("\n", array(
				'/**',
				' * This is only for the \'smf\' file cache system. It is the path to the cache directory.',
				' * It is also recommended that you place this in /tmp/ if you are going to use this.',
				' *',
				' * @var string',
				' */',
			)),
			'default' => 'dirname(__FILE__) . \'/cache\'',
			'raw_default' => true,
			'type' => 'string',
		),
		'image_proxy_enabled' => array(
			'text' => implode("\n", array(
				'',
				'########## Image Proxy ##########',
				'# This is done entirely in Settings.php to avoid loading the DB while serving the images',
				'/**',
				' * Whether the proxy is enabled or not',
				' *',
				' * @var bool',
				' */',
			)),
			'default' => true,
			'type' => 'boolean',
		),
		'image_proxy_secret' => array(
			'text' => implode("\n", array(
				'/**',
				' * Secret key to be used by the proxy',
				' *',
				' * @var string',
				' */',
			)),
			'default' => 'smfisawesome',
			'type' => 'string',
		),
		'image_proxy_maxsize' => array(
			'text' => implode("\n", array(
				'/**',
				' * Maximum file size (in KB) for individual files',
				' *',
				' * @var int',
				' */',
			)),
			'default' => 5192,
			'type' => 'integer',
		),
		'boarddir' => array(
			'text' => implode("\n", array(
				'',
				'########## Directories/Files ##########',
				'# Note: These directories do not have to be changed unless you move things.',
				'/**',
				' * The absolute path to the forum\'s folder. (not just \'.\'!)',
				' *',
				' * @var string',
				' */',
			)),
			'default' => 'dirname(__FILE__)',
			'raw_default' => true,
			'type' => 'string',
		),
		'sourcedir' => array(
			'text' => implode("\n", array(
				'/**',
				' * Path to the Sources directory.',
				' *',
				' * @var string',
				' */',
			)),
			'default' => 'dirname(__FILE__) . \'/Sources\'',
			'raw_default' => true,
			'type' => 'string',
		),
		'packagesdir' => array(
			'text' => implode("\n", array(
				'/**',
				' * Path to the Packages directory.',
				' *',
				' * @var string',
				' */',
			)),
			'default' => 'dirname(__FILE__) . \'/Packages\'',
			'raw_default' => true,
			'type' => 'string',
		),
		'tasksdir' => array(
			'text' => implode("\n", array(
				'/**',
				' * Path to the tasks directory.',
				' *',
				' * @var string',
				' */',
			)),
			'default' => '$sourcedir . \'/tasks\'',
			'raw_default' => true,
			'type' => 'string',
		),
		array(
			'text' => implode("\n", array(
				'',
				'# Make sure the paths are correct... at least try to fix them.',
				'if (!is_dir(realpath($boarddir)) && file_exists(dirname(__FILE__) . \'/agreement.txt\'))',
				'	$boarddir = dirname(__FILE__);',
				'if (!is_dir(realpath($sourcedir)) && is_dir($boarddir . \'/Sources\'))',
				'	$sourcedir = $boarddir . \'/Sources\';',
				'if (!is_dir(realpath($tasksdir)) && is_dir($sourcedir . \'/tasks\'))',
				'	$tasksdir = $sourcedir . \'/tasks\';',
				'if (!is_dir(realpath($packagesdir)) && is_dir($boarddir . \'/Packages\'))',
				'	$packagesdir = $boarddir . \'/Packages\';',
				'if (!is_dir(realpath($cachedir)) && is_dir($boarddir . \'/cache\'))',
				'	$cachedir = $boarddir . \'/cache\';',
			)),
			'search_pattern' => '~\n?(#[^\n]+)?(?:\n\h*if\s*\((?:\!file_exists\(\$(?'.'>boarddir|sourcedir|tasksdir|packagesdir|cachedir)\)|\!is_dir\(realpath\(\$(?'.'>boarddir|sourcedir|tasksdir|packagesdir|cachedir)\)\))[^;]+\n\h*\$(?'.'>boarddir|sourcedir|tasksdir|packagesdir|cachedir)[^\n]+;)+~sm',
		),
		'db_character_set' => array(
			'text' => implode("\n", array(
				'',
				'######### Legacy Settings #########',
				'# UTF-8 is now the only character set supported in 2.1.',
			)),
			'default' => 'utf8',
			'type' => 'string',
		),
		'db_show_debug' => array(
			'text' => implode("\n", array(
				'',
				'######### Developer Settings #########',
				'# Show debug info.',
			)),
			'default' => false,
			'auto_delete' => 2,
			'type' => 'boolean',
		),
		array(
			'text' => implode("\n", array(
				'',
				'########## Error-Catching ##########',
				'# Note: You shouldn\'t touch these settings.',
				'if (file_exists((isset($cachedir) ? $cachedir : dirname(__FILE__)) . \'/db_last_error.php\'))',
				'	include((isset($cachedir) ? $cachedir : dirname(__FILE__)) . \'/db_last_error.php\');',
				'',
				'if (!isset($db_last_error))',
				'{',
				'	// File does not exist so lets try to create it',
				'	file_put_contents((isset($cachedir) ? $cachedir : dirname(__FILE__)) . \'/db_last_error.php\', \'<\' . \'?\' . "php\n" . \'$db_last_error = 0;\' . "\n" . \'?\' . \'>\');',
				'	$db_last_error = 0;',
				'}',
			)),
			// Designed to match both 2.0 and 2.1 versions of this code.
			'search_pattern' => '~\n?#+ Error.Catching #+\n[^\n]*?settings\.\n(?:\$db_last_error = \d{1,11};|if \(file_exists.*?\$db_last_error = 0;(?' . '>\s*}))(?=\n|\?' . '>|$)~s',
		),
		// Temporary variable used during the upgrade process.
		'upgradeData' => array(
			'default' => '',
			'auto_delete' => 1,
			'type' => 'string',
		),
		// This should be removed if found.
		'db_last_error' => array(
			'default' => 0,
			'auto_delete' => 1,
			'type' => 'integer',
		),
	);

	// Allow mods the option to define comments, defaults, etc., for their settings.
	// Check if function exists, in case we are calling from installer or upgrader.
	if (function_exists('call_integration_hook'))
		call_integration_hook('integrate_update_settings_file', array(&$settings_defs));

	// If Settings.php is empty or invalid, try to recover using whatever is in $GLOBALS.
	if ($settings_vars === array())
	{
		foreach ($settings_defs as $var => $setting_def)
			if (isset($GLOBALS[$var]))
				$settings_vars[$var] = $GLOBALS[$var];

		$new_settings_vars = array_merge($settings_vars, $config_vars);
	}

	// During install/upgrade, don't set anything until we're ready for it.
	if (defined('SMF_INSTALLING') && empty($rebuild))
	{
		foreach ($settings_defs as $var => $setting_def)
			if (!in_array($var, array_keys($new_settings_vars)) && !is_int($var))
				unset($settings_defs[$var]);
	}

	/*******************************
	 * PART 2: Build substitutions *
	 *******************************/

	$type_regex = array(
		'string' =>
			'(?:' .
				// match the opening quotation mark...
				'(["\'])' .
				// then any number of other characters or escaped quotation marks...
				'(?:.(?!\\1)|\\\(?=\\1))*.?' .
				// then the closing quotation mark.
				'\\1' .
				// Maybe there's a second string concatenated to this one.
				'(?:\s*\.\s*)*' .
			')+',
		// Some numeric values might have been stored as strings.
		'integer' =>  '["\']?[+-]?\d+["\']?',
		'double' =>  '["\']?[+-]?\d+\.\d+([Ee][+-]\d+)?["\']?',
		// Some boolean values might have been stored as integers.
		'boolean' =>  '(?i:TRUE|FALSE|(["\']?)[01]\b\\1)',
		'NULL' =>  '(?i:NULL)',
		// These use a PCRE subroutine to match nested arrays.
		'array' =>  'array\s*(\((?'.'>[^()]|(?1))*\))',
		'object' =>  '\w+::__set_state\(array\s*(\((?'.'>[^()]|(?1))*\))\)',
	);

	/*
	 * The substitutions take place in one of two ways:
	 *
	 *  1: The search_pattern regex finds a string in Settings.php, which is
	 *     temporarily replaced by a placeholder. Once all the placeholders
	 *     have been inserted, each is replaced by the final replacement string
	 *     that we want to use. This is the standard method.
	 *
	 *  2: The search_pattern regex finds a string in Settings.php, which is
	 *     then deleted by replacing it with an empty placeholder. Then after
	 *     all the real placeholders have been dealt with, the replace_pattern
	 *     regex finds where to insert the final replacement string that we
	 *     want to use. This method is for special cases.
	 */
	$prefix = mt_rand() . '-';
	$neg_index = -1;
	$substitutions = array(
		$neg_index-- => array(
			'search_pattern' => '~^\s*<\?(php\b)?\n?~',
			'placeholder' => '',
			'replace_pattern' => '~^~',
			'replacement' => '<' . "?php\n",
		),
		$neg_index-- => array(
			'search_pattern' => '~\S\K\s*(\?' . '>)?\s*$~',
			'placeholder' => "\n" . md5($prefix . '?' . '>'),
			'replacement' => "\n\n?" . '>',
		),
		// Remove the code that redirects to the installer.
		$neg_index-- => array(
			'search_pattern' => '~^if\s*\(file_exists\(dirname\(__FILE__\)\s*\.\s*\'/install\.php\'\)\)\s*(?:({(?'.'>[^{}]|(?1))*})\h*|header(\((?' . '>[^()]|(?2))*\));\n)~m',
			'placeholder' => '',
		),
	);

	if (defined('SMF_INSTALLING'))
		$substitutions[$neg_index--] = array(
			'search_pattern' => '~/\*.*?SMF\s+1\.\d.*?\*/~s',
			'placeholder' => '',
		);

	foreach ($settings_defs as $var => $setting_def)
	{
		$placeholder = md5($prefix . $var);
		$replacement = '';

		if (!empty($setting_def['text']))
		{
			// Special handling for the license block: always at the beginning.
			if (strpos($setting_def['text'], "* @package SMF\n") !== false)
			{
				$substitutions[$var]['search_pattern'] = $setting_def['search_pattern'];
				$substitutions[$var]['placeholder'] = '';
				$substitutions[-1]['replacement'] .= $setting_def['text'] . "\n";
			}
			// Special handling for the Error-Catching block: always at the end.
			elseif (strpos($setting_def['text'], 'Error-Catching') !== false)
			{
				$errcatch_var = $var;

The assignment to $errcatch_var is dead and can be removed.

				$substitutions[$var]['search_pattern'] = $setting_def['search_pattern'];
				$substitutions[$var]['placeholder'] = '';
				$substitutions[-2]['replacement'] = "\n" . $setting_def['text'] . $substitutions[-2]['replacement'];
			}
			// The text is the whole thing (code blocks, etc.)
			elseif (is_int($var))
			{
				// Remember the path correcting code for later.
				if (strpos($setting_def['text'], '# Make sure the paths are correct') !== false)
					$pathcode_var = $var;

				if (!empty($setting_def['search_pattern']))
					$substitutions[$var]['search_pattern'] = $setting_def['search_pattern'];
				else
					$substitutions[$var]['search_pattern'] = '~' . preg_quote($setting_def['text'], '~') . '~';

				$substitutions[$var]['placeholder'] = $placeholder;

				$replacement .= $setting_def['text'] . "\n";
			}
			// We only include comments when rebuilding.
			elseif (!empty($rebuild))
				$replacement .= $setting_def['text'] . "\n";
		}

		if (is_string($var))
		{
			// Ensure the value is good.
			if (in_array($var, array_keys($new_settings_vars)))
			{
				// Objects without a __set_state method need a fallback.
				if (is_object($new_settings_vars[$var]) && !method_exists($new_settings_vars[$var], '__set_state'))
				{
					if (method_exists($new_settings_vars[$var], '__toString'))
						$new_settings_vars[$var] = (string) $new_settings_vars[$var];
					else
						$new_settings_vars[$var] = (array) $new_settings_vars[$var];
				}

				// Normalize the type if necessary.
				if (isset($setting_def['type']))
				{
					$expected_types = (array) $setting_def['type'];
					$var_type = gettype($new_settings_vars[$var]);

					// Variable is not of an expected type.
					if (!in_array($var_type, $expected_types))
					{
						// Passed in an unexpected array.
						if ($var_type == 'array')
						{
							$temp = reset($new_settings_vars[$var]);

							// Use the first element if there's only one and it is a scalar.
							if (count($new_settings_vars[$var]) === 1 && is_scalar($temp))
								$new_settings_vars[$var] = $temp;

							// Or keep the old value, if that is good.
							elseif (isset($settings_vars[$var]) && in_array(gettype($settings_vars[$var]), $expected_types))
								$new_settings_vars[$var] = $settings_vars[$var];

							// Fall back to the default
							else
								$new_settings_vars[$var] = $setting_def['default'];
						}

						// Cast it to whatever type was expected.
						// Note: the order of the types in this loop matters.
						foreach (array('boolean', 'integer', 'double', 'string', 'array') as $to_type)
						{
							if (in_array($to_type, $expected_types))
							{
								settype($new_settings_vars[$var], $to_type);
								break;
							}
						}
					}
				}
			}
			// Abort if a required one is undefined (unless we're installing).
			elseif (!empty($setting_def['required']) && !defined('SMF_INSTALLING'))
				return false;

			// Create the search pattern.
			if (!empty($setting_def['search_pattern']))
				$substitutions[$var]['search_pattern'] = $setting_def['search_pattern'];
			else
			{
				$var_pattern = array();

				if (isset($setting_def['type']))
				{
					foreach ((array) $setting_def['type'] as $type)
						$var_pattern[] = $type_regex[$type];
				}

				if (in_array($var, array_keys($config_vars)))
				{
					$var_pattern[] = @$type_regex[gettype($config_vars[$var])];

					if (is_string($config_vars[$var]) && strpos($config_vars[$var], dirname($settingsFile)) === 0)
						$var_pattern[] = '(?:__DIR__|dirname\(__FILE__\)) . \'' . (preg_quote(str_replace(dirname($settingsFile), '', $config_vars[$var]), '~')) . '\'';
				}

				if (in_array($var, array_keys($settings_vars)))
				{
					$var_pattern[] = @$type_regex[gettype($settings_vars[$var])];

					if (is_string($settings_vars[$var]) && strpos($settings_vars[$var], dirname($settingsFile)) === 0)
						$var_pattern[] = '(?:__DIR__|dirname\(__FILE__\)) . \'' . (preg_quote(str_replace(dirname($settingsFile), '', $settings_vars[$var]), '~')) . '\'';
				}

				if (!empty($setting_def['raw_default']) && $setting_def['default'] !== '')
				{
					$var_pattern[] = preg_replace('/\s+/', '\s+', preg_quote($setting_def['default'], '~'));

					if (strpos($setting_def['default'], 'dirname(__FILE__)') !== false)
						$var_pattern[] = preg_replace('/\s+/', '\s+', preg_quote(str_replace('dirname(__FILE__)', '__DIR__', $setting_def['default']), '~'));

					if (strpos($setting_def['default'], '__DIR__') !== false)
						$var_pattern[] = preg_replace('/\s+/', '\s+', preg_quote(str_replace('__DIR__', 'dirname(__FILE__)', $setting_def['default']), '~'));
				}

				$var_pattern = array_unique($var_pattern);

				$var_pattern = count($var_pattern) > 1 ? '(?:' . (implode('|', $var_pattern)) . ')' : $var_pattern[0];

				$substitutions[$var]['search_pattern'] = '~(?<=^|\s)\h*\$' . preg_quote($var, '~') . '\s*=\s*' . $var_pattern . ';~' . (!empty($context['utf8']) ? 'u' : '');

The variable $context seems to never exist and therefore empty should always be true.

			}

			// Next create the placeholder or replace_pattern.
			if (!empty($setting_def['replace_pattern']))
				$substitutions[$var]['replace_pattern'] = $setting_def['replace_pattern'];
			else
				$substitutions[$var]['placeholder'] = $placeholder;

			// Now create the replacement.
			// A setting to delete.
			if (!empty($setting_def['auto_delete']) && empty($new_settings_vars[$var]))
			{
				if ($setting_def['auto_delete'] === 2 && empty($rebuild) && in_array($var, array_keys($new_settings_vars)))
				{
					$replacement .= '$' . $var . ' = ' . ($new_settings_vars[$var] === $setting_def['default'] && !empty($setting_def['raw_default']) ? sprintf($new_settings_vars[$var]) : smf_var_export($new_settings_vars[$var], true)) . ";";

The call to smf_var_export() has too many arguments starting with true.

				}
				else
				{
					$replacement = '';

					// This is just for cosmetic purposes. Removes the blank line.
					$substitutions[$var]['search_pattern'] = str_replace('(?<=^|\s)', '\n?', $substitutions[$var]['search_pattern']);
				}
			}
			// Add this setting's value.
			elseif (in_array($var, array_keys($new_settings_vars)))
			{
				$replacement .= '$' . $var . ' = ' . ($new_settings_vars[$var] === $setting_def['default'] && !empty($setting_def['raw_default']) ? sprintf($new_settings_vars[$var]) : smf_var_export($new_settings_vars[$var], true)) . ";";
			}
			// Fall back to the default value.
			elseif (isset($setting_def['default']))
			{
				$replacement .= '$' . $var . ' = ' . (!empty($setting_def['raw_default']) ? sprintf($setting_def['default']) : smf_var_export($setting_def['default'], true)) . ';';
			}
			// This shouldn't happen, but we've got nothing.
			else
				$replacement .= '$' . $var . ' = null;';
		}

		$substitutions[$var]['replacement'] = $replacement;

		// We're done with this one.
		unset($new_settings_vars[$var]);
	}

	// Any leftovers to deal with?
	foreach ($new_settings_vars as $var => $val)
	{
		$var_pattern = array();

		if (in_array($var, array_keys($config_vars)))
			$var_pattern[] = $type_regex[gettype($config_vars[$var])];

		if (in_array($var, array_keys($settings_vars)))
			$var_pattern[] = $type_regex[gettype($settings_vars[$var])];

		$var_pattern = array_unique($var_pattern);

		$var_pattern = count($var_pattern) > 1 ? '(?:' . (implode('|', $var_pattern)) . ')' : $var_pattern[0];

		$placeholder = md5($prefix . $var);

		$substitutions[$var]['search_pattern'] = '~(?<=^|\s)\h*\$' . preg_quote($var, '~') . '\s*=\s*' . $var_pattern . ';~' . (!empty($context['utf8']) ? 'u' : '');
		$substitutions[$var]['placeholder'] = $placeholder;
		$substitutions[$var]['replacement'] = '$' . $var . ' = ' . smf_var_export($val, true) . ";";
	}

	// During an upgrade, some of the path variables may not have been declared yet.
	if (defined('SMF_INSTALLING') && empty($rebuild))
	{
		preg_match_all('~^\h*\$(\w+)\s*=\s*~m', $substitutions[$pathcode_var]['replacement'], $matches);

The variable $pathcode_var does not seem to be defined for all execution paths leading up to this point.

		$missing_pathvars = array_diff($matches[1], array_keys($substitutions));

		if (!empty($missing_pathvars))
		{
			foreach ($missing_pathvars as $var)
			{
				$substitutions[$pathcode_var]['replacement'] = preg_replace('~\nif[^\n]+\$' . $var . '[^\n]+\n\h*\$' . $var . ' = [^\n]+~', '', $substitutions[$pathcode_var]['replacement']);
			}
		}
	}

	// It's important to do the numbered ones before the named ones, or messes happen.
	uksort($substitutions, function($a, $b) {
		if (is_int($a) && is_int($b))
			return $a > $b;
		elseif (is_int($a))
			return -1;
		elseif (is_int($b))
			return 1;
		else
			return strcasecmp($b, $a);
	});

	/******************************
	 * PART 3: Content processing *
	 ******************************/

	/* 3.a: Get the content of Settings.php and make sure it is good. */

	// Retrieve the contents of Settings.php and normalize the line endings.
	$settingsText = trim(strtr(file_get_contents($settingsFile), array("\r\n" => "\n", "\r" => "\n")));

	// If Settings.php is empty or corrupt for some reason, see if we can recover.
	if ($settingsText == '' || substr($settingsText, 0, 5) !== '<' . '?php')
	{
		// Try restoring from the backup.
		if (file_exists(dirname($settingsFile) . '/Settings_bak.php'))
			$settingsText = strtr(file_get_contents(dirname($settingsFile) . '/Settings_bak.php'), array("\r\n" => "\n", "\r" => "\n"));

		// Backup is bad too? Our only option is to create one from scratch.
		if ($settingsText == '' || substr($settingsText, 0, 5) !== '<' . '?php' || substr($settingsText, -2) !== '?' . '>')
		{
			$settingsText = '<' . "?php\n";
			foreach ($settings_defs as $var => $setting_def)
			{
				if (!empty($setting_def['text']) && strpos($substitutions[$var]['replacement'], $setting_def['text']) === false)
					$substitutions[$var]['replacement'] = $setting_def['text'] . "\n" . $substitutions[$var]['replacement'];

				$settingsText .= $substitutions[$var]['replacement'] . "\n";
			}
			$settingsText .= "\n\n?" . '>';
			$rebuild = true;
		}
	}

	// Settings.php is unlikely to contain any heredocs, but just in case...
	if (preg_match_all('/<<<(\'?)(\w+)\'?\n(.*?)\n\2;$/m', $settingsText, $matches))
	{
		foreach ($matches[0] as $mkey => $heredoc)
		{
			if (!empty($matches[1][$mkey]))
				$heredoc_replacements[$heredoc] = var_export($matches[3][$mkey], true) . ';';
			else
				$heredoc_replacements[$heredoc] = '"' . strtr(substr(var_export($matches[3][$mkey], true), 1, -1), array("\\'" => "'", '"' => '\"')) . '";';
		}

		$settingsText = strtr($settingsText, $heredoc_replacements);

The variable $heredoc_replacements seems to be defined by a foreach iteration on line 1268. Are you sure the iterator is never empty, otherwise this variable is not defined?

	}

	/* 3.b: Loop through all our substitutions to insert placeholders, etc. */

	$last_var = null;
	$bare_settingsText = $settingsText;
	$force_before_pathcode = array();
	foreach ($substitutions as $var => $substitution)
	{
		$placeholders[$var] = $substitution['placeholder'];

		if (!empty($substitution['placeholder']))
		{
			$simple_replacements[$substitution['placeholder']] = $substitution['replacement'];
		}
		elseif (!empty($substitution['replace_pattern']))
		{
			$replace_patterns[$var] = $substitution['replace_pattern'];
			$replace_strings[$var] = $substitution['replacement'];
		}

		if (strpos($substitutions[$pathcode_var]['replacement'], '$' . $var . ' = ') !== false)
			$force_before_pathcode[] = $var;

		// Look before you leap.
		preg_match_all($substitution['search_pattern'], $bare_settingsText, $matches);

		if ((is_string($var) || $var === $pathcode_var) && count($matches[0]) !== 1 && $substitution['replacement'] !== '')
		{
			// More than one instance of the variable = not good.
			if (count($matches[0]) > 1)
			{
				if (is_string($var))
				{
					// Maybe we can try something more interesting?
					$sp = substr($substitution['search_pattern'], 1);

					if (strpos($sp, '(?<=^|\s)') === 0)
						$sp = substr($sp, 9);

					if (strpos($sp, '^') === 0 || strpos($sp, '(?<') === 0)
						return false;

					// See if we can exclude `if` blocks, etc., to narrow down the matches.
					// @todo Multiple layers of nested brackets might confuse this.
					$sp = '~(?:^|//[^\n]+c\n|\*/|[;}]|' . implode('|', array_filter($placeholders)) . ')\s*' . (strpos($sp, '\K') === false ? '\K' : '') . $sp;

The variable $placeholders seems to be defined later in this foreach loop on line 1286. Are you sure it is defined here?

					preg_match_all($sp, $settingsText, $matches);
				}
				else
					$sp = $substitution['search_pattern'];

				// Found at least some that are simple assignment statements.
				if (count($matches[0]) > 0)
				{
					// Remove any duplicates.
					if (count($matches[0]) > 1)
						$settingsText = preg_replace($sp, '', $settingsText, count($matches[0]) - 1);

					// Insert placeholder for the last one.
					$settingsText = preg_replace($sp, $substitution['placeholder'], $settingsText, 1);
				}

				// All instances are inside more complex code structures.
				else
				{
					// Only safe option at this point is to skip it.
					unset($substitutions[$var], $new_settings_vars[$var], $settings_defs[$var], $simple_replacements[$substitution['placeholder']], $replace_patterns[$var], $replace_strings[$var]);

					continue;
				}
			}
			// No matches found.
			elseif (count($matches[0]) === 0)
			{
				$found = false;
				$in_c = in_array($var, array_keys($config_vars));
				$in_s = in_array($var, array_keys($settings_vars));

				// Is it in there at all?
				if (!preg_match('~(^|\s)\$' . preg_quote($var, '~') . '\s*=\s*~', $bare_settingsText))
				{
					// It's defined by Settings.php, but not by code in the file.
					// Probably done via an include or something. Skip it.
					if ($in_s)
						unset($substitutions[$var], $settings_defs[$var]);

					// Admin is explicitly trying to set this one, so we'll handle
					// it as if it were a new custom setting being added.
					elseif ($in_c)
						$new_settings_vars[$var] = $config_vars[$var];

					continue;
				}

				// It's in there somewhere, so check if the value changed type.
				foreach (array('scalar', 'object', 'array') as $type)
				{
					// Try all the other scalar types first.
					if ($type == 'scalar')
						$sp = '(?:' . (implode('|', array_diff_key($type_regex, array($in_c ? gettype($config_vars[$var]) : ($in_s ? gettype($settings_vars[$var]) : PHP_INT_MAX) => '', 'array' => '', 'object' => '')))) . ')';

					// Maybe it's an object? (Probably not, but we should check.)
					elseif ($type == 'object')
					{
						if (strpos($settingsText, '__set_state') === false)
							continue;

						$sp = $type_regex['object'];
					}

					// Maybe it's an array?
					else
						$sp = $type_regex['array'];

					if (preg_match('~(^|\s)\$' . preg_quote($var, '~') . '\s*=\s*' . $sp . '~', $bare_settingsText, $derp))
					{
						$settingsText = preg_replace('~(^|\s)\$' . preg_quote($var, '~') . '\s*=\s*' . $sp . '~', $substitution['placeholder'], $settingsText);
						$found = true;
						break;
					}
				}

				// Something weird is going on. Better just leave it alone.
				if (!$found)
				{
					// $var? What $var? Never heard of it.
					unset($substitutions[$var], $new_settings_vars[$var], $settings_defs[$var], $simple_replacements[$substitution['placeholder']], $replace_patterns[$var], $replace_strings[$var]);
					continue;
				}
			}
		}
		// Good to go, so insert our placeholder.
		else
			$settingsText = preg_replace($substitution['search_pattern'], $substitution['placeholder'], $settingsText);

		// Once the code blocks are done, we want to compare to a version without comments.
		if (is_int($last_var) && is_string($var))
			$bare_settingsText = strip_php_comments($settingsText);

		$last_var = $var;
	}

	// Rebuilding requires more work.
	if (!empty($rebuild))
	{
		// Strip out the leading and trailing placeholders to prevent duplication.
		$settingsText = str_replace(array($substitutions[-1]['placeholder'], $substitutions[-2]['placeholder']), '', $settingsText);

		// Strip out all our standard comments.
		foreach ($settings_defs as $var => $setting_def)
		{
			if (isset($setting_def['text']))
				$settingsText = strtr($settingsText, array($setting_def['text'] . "\n" => '', $setting_def['text'] => '',));
		}

		// We need to refresh $bare_settingsText at this point.
		$bare_settingsText = strip_php_comments($settingsText);

		// Fix up whitespace to make comparison easier.
		foreach ($placeholders as $placeholder)
		{
			$bare_settingsText = str_replace(array($placeholder . "\n\n", $placeholder), $placeholder . "\n", $bare_settingsText);
		}
		$bare_settingsText = preg_replace('/\h+$/m', '', rtrim($bare_settingsText));

		/*
		 * Divide the existing content into sections.
		 * The idea here is to make sure we don't mess with the relative position
		 * of any code blocks in the file, since that could break things. Within
		 * each section, however, we'll reorganize the content to match the
		 * default layout as closely as we can.
		 */
		$sections = array(array());
		$section_num = 0;
		$trimmed_placeholders = array_filter(array_map('trim', $placeholders));
		$newsection_placeholders = array();
		$all_custom_content = '';
		foreach ($substitutions as $var => $substitution)
		{
			if (is_int($var) && ($var === -2 || $var > 0) && isset($trimmed_placeholders[$var]) && strpos($bare_settingsText, $trimmed_placeholders[$var]) !== false)
				$newsection_placeholders[$var] = $trimmed_placeholders[$var];
		}
		foreach (preg_split('~(?<=' . implode('|', $trimmed_placeholders) . ')|(?=' . implode('|', $trimmed_placeholders) . ')~', $bare_settingsText) as $part)
		{
			$part = trim($part);

			if (empty($part))
				continue;

			// Build a list of placeholders for this section.
			if (in_array($part, $trimmed_placeholders) && !in_array($part, $newsection_placeholders))
			{
				$sections[$section_num][] = $part;
			}
			// Custom content and newsection_placeholders get their own sections.
			else
			{
				if (!empty($sections[$section_num]))
					++$section_num;

				$sections[$section_num][] = $part;

				++$section_num;

				if (!in_array($part, $trimmed_placeholders))
					$all_custom_content .= "\n" . $part;
			}
		}

		// And now, rebuild the content!
		$new_settingsText = '';
		$done_defs = array();
		$sectionkeys = array_keys($sections);
		foreach ($sections as $sectionkey => $section)
		{
			// Custom content needs to be preserved.
			if (count($section) === 1 && !in_array($section[0], $trimmed_placeholders))
			{
				$prev_section_end = $sectionkey < 1 ? 0 : strpos($settingsText, end($sections[$sectionkey - 1])) + strlen(end($sections[$sectionkey - 1]));
				$next_section_start = $sectionkey == end($sectionkeys) ? strlen($settingsText) : strpos($settingsText, $sections[$sectionkey + 1][0]);

				$new_settingsText .= "\n" . substr($settingsText, $prev_section_end, $next_section_start - $prev_section_end) . "\n";
			}
			// Put the placeholders in this section into canonical order.
			else
			{
				$section_parts = array_flip($section);
				$pathcode_reached = false;
				foreach ($settings_defs as $var => $setting_def)
				{
					if ($var === $pathcode_var)
						$pathcode_reached = true;

					// Already did this setting, so move on to the next.
					if (in_array($var, $done_defs))
						continue;

					// Stop when we hit a setting definition that will start a later section.
					if (isset($newsection_placeholders[$var]) && count($section) !== 1)
						break;

					// Stop when everything in this section is done, unless it's the last.
					// This helps maintain the relative position of any custom content.
					if (empty($section_parts) && $sectionkey < (count($sections) - 1))
						break;

					$p = trim($substitutions[$var]['placeholder']);

					// Can't do anything with an empty placeholder.
					if ($p === '')
						continue;

					// Does this need to be inserted before the path correction code?
					if (strpos($new_settingsText, trim($substitutions[$pathcode_var]['placeholder'])) !== false && in_array($var, $force_before_pathcode))
					{
						$new_settingsText = strtr($new_settingsText, array($substitutions[$pathcode_var]['placeholder'] => $p . "\n" . $substitutions[$pathcode_var]['placeholder']));

						$bare_settingsText .= "\n" . $substitutions[$var]['placeholder'];
						$done_defs[] = $var;
						unset($section_parts[trim($substitutions[$var]['placeholder'])]);
					}

					// If it's in this section, add it to the new text now.
					elseif (in_array($p, $section))
					{
						$new_settingsText .= "\n" . $substitutions[$var]['placeholder'];
						$done_defs[] = $var;
						unset($section_parts[trim($substitutions[$var]['placeholder'])]);
					}

					// Perhaps it is safe to reposition it anyway.
					elseif (is_string($var) && strpos($new_settingsText, $p) === false && strpos($all_custom_content, '$' . $var) === false)
					{
						$new_settingsText .= "\n" . $substitutions[$var]['placeholder'];
						$done_defs[] = $var;
						unset($section_parts[trim($substitutions[$var]['placeholder'])]);
					}

					// If this setting is missing entirely, fix it.
					elseif (strpos($bare_settingsText, $p) === false)
					{
						// Special case if the path code is missing. Put it near the end,
						// and also anything else that is missing that normally follows it.
						if (!isset($newsection_placeholders[$pathcode_var]) && $pathcode_reached === true && $sectionkey < (count($sections) - 1))
							break;

						$new_settingsText .= "\n" . $substitutions[$var]['placeholder'];
						$bare_settingsText .= "\n" . $substitutions[$var]['placeholder'];
						$done_defs[] = $var;
						unset($section_parts[trim($substitutions[$var]['placeholder'])]);
					}
				}
			}
		}
		$settingsText = $new_settingsText;

		// Restore the leading and trailing placeholders as necessary.
		foreach (array(-1, -2) as $var)
		{
			if (!empty($substitutions[$var]['placeholder']) && strpos($settingsText, $substitutions[$var]['placeholder']) === false);
			{
				$settingsText = ($var == -1 ? $substitutions[$var]['placeholder'] : '') . $settingsText . ($var == -2 ? $substitutions[$var]['placeholder'] : '');
			}
		}
	}
	// Even if not rebuilding, there are a few variables that may need to be moved around.
	else
	{
		$pathcode_pos = strpos($settingsText, $substitutions[$pathcode_var]['placeholder']);

		if ($pathcode_pos !== false)
		{
			foreach ($force_before_pathcode as $var)
			{
				if (!empty($substitutions[$var]['placeholder']) && strpos($settingsText, $substitutions[$var]['placeholder']) > $pathcode_pos)
				{
					$settingsText = strtr($settingsText, array(
						$substitutions[$var]['placeholder'] => '',
						$substitutions[$pathcode_var]['placeholder'] => $substitutions[$var]['placeholder'] . "\n" . $substitutions[$pathcode_var]['placeholder'],
					));
				}
			}
		}
	}

	/* 3.c: Replace the placeholders with the final values */

	// Where possible, perform simple substitutions.
	$settingsText = strtr($settingsText, $simple_replacements);

The variable $simple_replacements does not seem to be defined for all execution paths leading up to this point.

	// Deal with any complicated ones.
	if (!empty($replace_patterns))
		$settingsText = preg_replace($replace_patterns, $replace_strings, $settingsText);

The variable $replace_strings does not seem to be defined for all execution paths leading up to this point.

	// Make absolutely sure that the path correction code is included.
	if (strpos($settingsText, $substitutions[$pathcode_var]['replacement']) === false)
		$settingsText = preg_replace('~(?=\n#+ Error.Catching #+)~', "\n" . $substitutions[$pathcode_var]['replacement'] . "\n", $settingsText);

	// If we did not rebuild, do just enough to make sure the thing is viable.
	if (empty($rebuild))
	{
		// We need to refresh $bare_settingsText again, and remove the code blocks from it.
		$bare_settingsText = $settingsText;
		foreach ($substitutions as $var => $substitution)
		{
			if (!is_int($var))
				break;

			if (isset($substitution['replacement']))
				$bare_settingsText = str_replace($substitution['replacement'], '', $bare_settingsText);
		}
		$bare_settingsText = strip_php_comments($bare_settingsText);

		// Now insert any defined settings that are missing.
		$pathcode_reached = false;
		foreach ($settings_defs as $var => $setting_def)
		{
			if ($var === $pathcode_var)
				$pathcode_reached = true;

			if (is_int($var))
				continue;

			// Do nothing if it is already in there.
			if (preg_match($substitutions[$var]['search_pattern'], $bare_settingsText))
				continue;

			// Insert it either before or after the path correction code, whichever is appropriate.
			if (!$pathcode_reached || in_array($var, $force_before_pathcode))
			{
				$settingsText = preg_replace($substitutions[$pathcode_var]['search_pattern'], $substitutions[$var]['replacement'] . "\n$0", $settingsText);
			}
			else
			{
				$settingsText = preg_replace($substitutions[$pathcode_var]['search_pattern'], "$0\n" . $substitutions[$var]['replacement'], $settingsText);
			}
		}
	}

	// If we have any brand new settings to add, do so.
	foreach ($new_settings_vars as $var => $val)
	{
		if (isset($substitutions[$var]) && !preg_match($substitutions[$var]['search_pattern'], $settingsText))
		{
			if (!isset($settings_defs[$var]) && strpos($settingsText, '# Custom Settings #') === false)
				$settingsText = preg_replace('~(?=\n#+ Error.Catching #+)~', "\n\n######### Custom Settings #########\n", $settingsText);

			$settingsText = preg_replace('~(?=\n#+ Error.Catching #+)~', $substitutions[$var]['replacement'] . "\n", $settingsText);
		}
	}

	// This is just cosmetic. Get rid of extra lines of whitespace.
	$settingsText = preg_replace('~\n\s*\n~', "\n\n", $settingsText);

	/**************************************
	 * PART 4: Check syntax before saving *
	 **************************************/

	$temp_sfile = tempnam(sm_temp_dir(), md5($prefix . 'Settings.php'));
	file_put_contents($temp_sfile, $settingsText);

	$result = get_current_settings(filemtime($temp_sfile), $temp_sfile);

	unlink($temp_sfile);

	// If the syntax is borked, try rebuilding to see if that fixes it.
	if ($result === false)

The condition $result === false is always false.

		return empty($rebuild) ? updateSettingsFile($config_vars, $keep_quotes, true) : false;

	/******************************************
	 * PART 5: Write updated settings to file *
	 ******************************************/

	$success = safe_file_write($settingsFile, $settingsText, dirname($settingsFile) . '/Settings_bak.php', $last_settings_change);

	// Remember this in case updateSettingsFile is called twice.
	$mtime = filemtime($settingsFile);

The assignment to $mtime is dead and can be removed.

	return $success;
}
?>