mb_strlen exists but mb_check_encoding undefined

[korobochkin]

Hi. I trying to use this amazing library in my work but still not understand what happens. I manually disable mbstring module in my php-7 setup for testing purposes. But all of this functions from this library still not defined.

I debug into the bootstrap.php and see that function_exists('mb_strlen') returns true. I hope that I'm doing something wrong but I can't explain that happening.

Why mb_strlen() defined if mbstring module is disabled?

$exists = function_exists('mb_strlen');
(bool)true

$phpVersion = phpversion();
7.0.12-1+deb.sury.org~trusty+1

$extensions = get_loaded_extensions();
array (
  0 => 'Core',
  1 => 'date',
  2 => 'libxml',
  3 => 'openssl',
  4 => 'pcre',
  5 => 'zlib',
  6 => 'filter',
  7 => 'hash',
  8 => 'Reflection',
  9 => 'SPL',
  10 => 'session',
  11 => 'standard',
  12 => 'cgi-fcgi',
  13 => 'mysqlnd',
  14 => 'PDO',
  15 => 'xml',
  16 => 'bcmath',
  17 => 'calendar',
  18 => 'ctype',
  19 => 'curl',
  20 => 'dom',
  21 => 'exif',
  22 => 'fileinfo',
  23 => 'ftp',
  24 => 'gd',
  25 => 'gettext',
  26 => 'iconv',
  27 => 'imagick',
  28 => 'imap',
  29 => 'json',
  30 => 'mcrypt',
  31 => 'memcache',
  32 => 'mysqli',
  33 => 'pdo_mysql',
  34 => 'Phar',
  35 => 'posix',
  36 => 'readline',
  37 => 'shmop',
  38 => 'SimpleXML',
  39 => 'soap',
  40 => 'sockets',
  41 => 'ssh2',
  42 => 'sysvmsg',
  43 => 'sysvsem',
  44 => 'sysvshm',
  45 => 'tokenizer',
  46 => 'wddx',
  47 => 'xmlreader',
  48 => 'xmlwriter',
  49 => 'xsl',
  50 => 'zip',
  51 => 'Zend OPcache',
  52 => 'xdebug',
)

[keradus]

but all of this functions from this library still not defined.
I debug into the bootstrap.php and see that function_exists('mb_strlen'); returns true

so, your PHP claims it knows about mb_strlen function, so polyfill is working properly for you. The method is registered not by module, but via this polyfill.

[korobochkin]

@keradus yes, I expect this behaviour. But instead I have fatal error :

Fatal error: Uncaught Error: Call to undefined function Symfony\Component\Validator\Constraints\mb_check_encoding() in /srv/www/wordpress-default/wp-content/plugins/setka-editor/vendor/symfony/validator/Constraints/LengthValidator.php on line 42

The code from my first message I writed directly in bootstrap.php before if (!function_exists('mb_strlen')). So right in bootstrap.php function_exists('mb_strlen') returns true but all of this functions such as mb_check_encoding() not defined because I don't have an extension (manually disabled) and if (!function_exists('mb_strlen')) statement working not as expected.

[korobochkin]

Ah!. I understand what it is. As you can noticed before - I'm using this libraby (Symfony Validator) in WordPress. And WordPress have their own mb_strlen() in wp-includes/compat.php:

if ( ! function_exists( 'mb_strlen' ) ) :
    function mb_strlen( $str, $encoding = null ) {
        return _mb_strlen( $str, $encoding );
    }
endif;

Oh! Look like I'm in trouble :)

[keradus]

keradus@keradus:~$ php --version
PHP 7.1.0RC3 (cli) ( NTS )
Copyright (c) 1997-2016 The PHP Group
Zend Engine v3.1.0-dev, Copyright (c) 1998-2016 Zend Technologies
    with Zend OPcache v7.1.0RC3, Copyright (c) 1999-2016, by Zend Technologies
keradus@keradus:~$ php -m | grep mb
keradus@keradus:~$ php -r "var_dump(function_exists('mb_strlen'));"
bool(false)

[keradus]

buahahaha :D good one ;)
maybe you should propose WP to use this polyfill, as it's more full ? (eg we have that mb_check_encoding)

[korobochkin]

@keradus Thank you for your suggestions :) Spent a few hours to prepare server with PHP 7.0 and all the environment similar to the "bug reported environment". And only after it thought to search for function mb_strlen in WordPress source code :)

I'd really like to WordPress used this and other Symfony packages (librarys) but it takes a long time for developement and older WordPress versions still unmodified (its bad for plugin developers who cares about backward compatibility).

[keradus]

well. one way or another I think that this issue could be closed.

[korobochkin]

Yes. Thank you for quick replies and support!

[keradus]

glad to help !