<?php

    /** No bugs detected in iconv. */
    const ICONV_OK = 0;

    /** Iconv truncates output if converting from UTF-8 to another
     *  character set with //IGNORE, and a non-encodable character is found */
    const ICONV_TRUNCATES = 1;

    /** Iconv does not support //IGNORE, making it unusable for
     *  transcoding purposes */
    const ICONV_UNUSABLE = 2;


    /**
     * iconv wrapper which mutes errors, but doesn't work around bugs.
     * @param string $in Input encoding
     * @param string $out Output encoding
     * @param string $text The text to convert
     * @return string
     */
    function unsafeIconv($in, $out, $text)
    {
        set_error_handler( 'muteErrorHandler');
        $r = iconv($in, $out, $text);
        restore_error_handler();
        return $r;
    }


    function muteErrorHandler($errno, $errstr)
    {
    }

        /**
     * glibc iconv has a known bug where it doesn't handle the magic
     * //IGNORE stanza correctly.  In particular, rather than ignore
     * characters, it will return an EILSEQ after consuming some number
     * of characters, and expect you to restart iconv as if it were
     * an E2BIG.  Old versions of PHP did not respect the errno, and
     * returned the fragment, so as a result you would see iconv
     * mysteriously truncating output. We can work around this by
     * manually chopping our input into segments of about 8000
     * characters, as long as PHP ignores the error code.  If PHP starts
     * paying attention to the error code, iconv becomes unusable.
     *
     * @return int Error code indicating severity of bug.
     */
    function testIconvTruncateBug()
    {
            // better not use iconv, otherwise infinite loop!
            $r = unsafeIconv('utf-8', 'ascii//IGNORE', "\xCE\xB1" . str_repeat('a', 9000));
            if ($r === false) {
                $code = ICONV_UNUSABLE;
            } elseif (($c = strlen($r)) < 9000) {
                $code = ICONV_TRUNCATES;
            } elseif ($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 = ICONV_OK;
            }
        return $code;
    }