Variable MB_CHECK_PHPConst
MB_CHECK_PHP: "if (!isset($GLOBALS['__pw_autoloader']) || !is_object($GLOBALS['__pw_autoloader'])) {\n\t$GLOBALS['__pw_autoloader'] = require '/drupal/autoload.php';\n}\n\n$cases = [\n\t'ascii' => 'abc',\n\t'valid accented' => \"caf\\xc3\\xa9\",\n\t'valid CJK' => \"\\xe4\\xbd\\xa0\\xe5\\xa5\\xbd\",\n\t'valid astral emoji' => \"\\xf0\\x9f\\x98\\x80\",\n\t'two bad bytes' => \"abc\\xff\\xfedef\",\n\t'lone continuation' => \"abc\\x80def\",\n\t'truncated 3-byte end' => \"abc\\xe4\\xbd\",\n\t'truncated 3-byte mid' => \"abc\\xe4\\xbddef\",\n\t'overlong C0' => \"abc\\xc0\\xafdef\",\n\t'surrogate ED A0 80' => \"abc\\xed\\xa0\\x80def\",\n\t'truncated 4-byte mid' => \"abc\\xf0\\x9fdef\",\n\t'F5 out of range' => \"abc\\xf5\\x80\\x80\\x80def\",\n];\n\n$out = [\n\t'mbstringExtension' => extension_loaded('mbstring'),\n\t'iconvExtension' => extension_loaded('iconv'),\n\t'wrappersInstalled' => function_exists('cfw_mb_installed'),\n\t'sanitizerPresent' => function_exists('cfw_mb_sanitize'),\n\t'cases' => [],\n];\n\nforeach ($cases as $label => $raw) {\n\t$out['cases'][$label] = [\n\t\t'in' => bin2hex($raw),\n\t\t'mb_substr' => mb_substr($raw, 0, 100000),\n\t\t'mb_strlen' => mb_strlen($raw),\n\t\t'mb_strtolower' => mb_strtolower($raw),\n\t\t// must NOT be sanitised: an invalid string has to still report invalid\n\t\t'mb_check_encoding' => mb_check_encoding($raw, 'UTF-8'),\n\t];\n}\n\necho json_encode($out);\n"