HTMLPurifier_Encoder::testIconvTruncateBug PHP Method

    public static function testIconvTruncateBug()
    {
        static $code = null;
        if ($code === null) {
            // better not use iconv, otherwise infinite loop!
            $r = self::unsafeIconv('utf-8', 'ascii//IGNORE', "α" . str_repeat('a', 9000));
            if ($r === false) {
                $code = self::ICONV_UNUSABLE;
            } elseif (($c = strlen($r)) < 9000) {
                $code = self::ICONV_TRUNCATES;
            } elseif ($c > 9000) {
                trigger_error('Your copy of iconv is extremely buggy. Please notify HTML Purifier maintainers: ' . 'include your iconv version as per phpversion()', E_USER_ERROR);
            } else {
                $code = self::ICONV_OK;
            }
        }
        return $code;
    }

 /**
  * Convert a string to UTF-8 based on configuration.
  * @param string $str The string to convert
  * @param HTMLPurifier_Config $config
  * @param HTMLPurifier_Context $context
  * @return string
  */
 public static function convertToUTF8($str, $config, $context)
 {
     $encoding = $config->get('Core.Encoding');
     if ($encoding === 'utf-8') {
         return $str;
     }
     static $iconv = null;
     if ($iconv === null) {
         $iconv = self::iconvAvailable();
     }
     if ($iconv && !$config->get('Test.ForceNoIconv')) {
         // unaffected by bugs, since UTF-8 support all characters
         $str = self::unsafeIconv($encoding, 'utf-8//IGNORE', $str);
         if ($str === false) {
             // $encoding is not a valid encoding
             trigger_error('Invalid encoding ' . $encoding, E_USER_ERROR);
             return '';
         }
         // If the string is bjorked by Shift_JIS or a similar encoding
         // that doesn't support all of ASCII, convert the naughty
         // characters to their true byte-wise ASCII/UTF-8 equivalents.
         $str = strtr($str, self::testEncodingSupportsASCII($encoding));
         return $str;
     } elseif ($encoding === 'iso-8859-1') {
         $str = utf8_encode($str);
         return $str;
     }
     $bug = HTMLPurifier_Encoder::testIconvTruncateBug();
     if ($bug == self::ICONV_OK) {
         trigger_error('Encoding not supported, please install iconv', E_USER_ERROR);
     } else {
         trigger_error('You have a buggy version of iconv, see https://bugs.php.net/bug.php?id=48147 ' . 'and http://sourceware.org/bugzilla/show_bug.cgi?id=13541', E_USER_ERROR);
     }
 }