mbstring overload fix

mbo.php

<?php

defined('MBO_ENCODING') || define('MBO_ENCODING', 'iso-8859-1');

function mbo_virtual($path, $debug = 0)
{
	static $realFiles = array();

	$cacheDir = __DIR__.'/cache/';

	$callFrom = debug_backtrace(0, 1);
	$callFile = $callFrom[0]['file'];

	$isRealPath = (substr($path, 0, 1) === '/');
	$isFromCache = (strpos($callFile, $cacheDir) === 0);

	if ($isRealPath && $isFromCache) {
		$realFile = realpath(str_replace($cacheDir, dirname($realFiles[$callFile]).'/', $path));
	} else {
		//TODO: check include paths
		//$paths = explode(':', get_include_path());
		$realFile = realpath($path);
	}

	if (!$realFile) {
		var_dump(compact('callFile', 'path', 'isRealPath', 'isFromCache', 'realPath'));
		die();
	}

	$cacheFile = $cacheDir.str_replace('/', '_', $realFile);
	if ($debug || !file_exists($cacheFile)) {
		if (!@file_put_contents($cacheFile, mbo_virtual_patch($realFile, $debug)))
			return $realFile;
	}

	$realFiles[$cacheFile] = $realFile;

	return $cacheFile;
}

function mbo_virtual_check($replace)
{
	$chars = count_chars($replace);
	return ($chars[ord('\'')] % 2 === 0 && $chars[ord('\"')] % 2 === 0 && $chars[ord('(')] === $chars[ord(')')]);
}

function mbo_virtual_patch($realFile, $debug)
{
	$realDir = dirname($realFile);

	$source = file_get_contents($realFile);

	$source = strtr($source, array(
		'__FILE__' => "'$realFile'",
		'__DIR__' => "'$realDir'",
	));

	$source = preg_replace_callback('/\b(require|include)(_once)?\b\s*?([^;\n]+);/', function($m) use($debug){
		return !mbo_virtual_check($m[3]) ? $m[0] : $m[1].$m[2].' mbo_virtual('.$m[3].', '.$debug.');';
	}, $source);

	return mbo_patch($source);
}

function mbo_patch($source, $revert = false)
{
	$output = '';

	if (is_array($revert)) {
		$replace = $revert;
	} else {
		$replace = [
			'strlen' => 'mbo_strlen',
			'strpos' => 'mbo_strpos',
			'strrpos' => 'mbo_strrpos',
			'substr' => 'mbo_substr',
			'strtolower' => 'mbo_strtolower',
			'strtoupper' => 'mbo_strtoupper',
			'stripos' => 'mbo_stripos',
			'strripos' => 'mbo_strripos',
			'strstr' => 'mbo_strstr',
			'stristr' => 'mbo_stristr',
			'strrchr' => 'mbo_strrchr',
			'substr_count' => 'mbo_substr_count',
		];

		if ($revert) {
			$replace = array_flip($replace);
		}
	}

	$tokens = token_get_all($source);
	foreach ($tokens as $i => $token) {
		if (!is_array($token)) {
			$output .= $token;
		} elseif ($token[0] === T_STRING && isset($replace[$token[1]])) {
			$isReplace = ($i === 0 || !is_array($tokens[$i - 1]) || ($tokens[$i - 1][0] !== T_DOUBLE_COLON && $tokens[$i - 1][0] !== T_OBJECT_OPERATOR));
			$output .= $isReplace ? $replace[$token[1]] : $token[1];
		} else {
			$output .= $token[1];
		}
	}

	return $output;
}

function mbo_strlen($string)
{
	return mb_strlen($string, MBO_ENCODING);
}

function mbo_strpos($haystack, $needle, $offset = 0)
{
	return mb_strpos($haystack, $needle, $offset, MBO_ENCODING);
}

function mbo_strrpos($haystack, $needle, $offset = 0)
{
	return mb_strrpos($haystack, $needle, $offset, MBO_ENCODING);
}

function mbo_substr($string, $start)
{
	$args = func_get_args();
	if (array_key_exists(2, $args))
		$length = $args[2];
	else
		$length = mb_strlen($string, MBO_ENCODING);

	return mb_substr($string, $start, $length, MBO_ENCODING);
}

function mbo_strtolower($string)
{
	return mb_strtolower($string, MBO_ENCODING);
}

function mbo_strtoupper($string)
{
	return mb_strtoupper($string, MBO_ENCODING);
}

function mbo_stripos($haystack, $needle, $offset = 0)
{
	return mb_stripos($haystack, $needle, $offset, MBO_ENCODING);
}

function mbo_strripos($haystack, $needle, $offset = 0)
{
	return mb_strripos($haystack, $needle, $offset, MBO_ENCODING);
}

function mbo_strstr($haystack, $needle, $before_needle = false)
{
	return mb_strstr($haystack, $needle, $before_needle, MBO_ENCODING);
}

function mbo_stristr($haystack, $needle, $before_needle = false)
{
	return mb_stristr($haystack, $needle, $before_needle, MBO_ENCODING);
}

function mbo_strrchr($haystack, $needle)
{
	$needle = mb_substr($needle, 0, 1, MBO_ENCODING);
	if (is_integer($needle))
		$needle = chr($needle);

	return mb_strrchr($haystack, $needle, false, MBO_ENCODING);
}

function mbo_substr_count($haystack, $needle, $offset = 0)
{
	$args = func_get_args();
	if (array_key_exists(3, $args))
		$length = $args[3];
	else
		$length = mb_strlen($haystack, MBO_ENCODING);

	$haystack = mb_substr($haystack, $offset, $length, MBO_ENCODING);

	return mb_substr_count($haystack, $needle, MBO_ENCODING);
}