// Replace this funtion with the original one!
function discover_pingback_server_uri($url, $timeout_bytes = 2048) {
	global $wp_version;

	$byte_count = 0;
	$contents = '';
	$headers = '';
	$pingback_str_dquote = 'rel="pingback"';
	$pingback_str_squote = 'rel=\'pingback\'';
	$x_pingback_str = 'x-pingback: ';
	$pingback_href_original_pos = 27;

	extract(parse_url($url));

	if (!isset($host)) {
		// Not an URL. This should never happen.
		return false;
	}

	$path  = (!isset($path)) ? '/'        : $path;
	$path .= (isset($query)) ? '?'.$query : '';
	$port  = (isset($port))  ? $port      : 80;

	// Try to connect to the server at $host
	$fp = @fsockopen($host, $port, $errno, $errstr, 2);
	if (!$fp) {
		// Couldn't open a connection to $host;
		return false;
	}

	// Send the HEAD request
	$request = "HEAD $path HTTP/1.1\r\nHost: $host\r\nUser-Agent: WordPress-Checker/$wp_version \r\n\r\n";
	//	ob_end_flush();
	fputs($fp, $request);

	// Let's check for an X-Pingback header first
	while (!feof($fp)) {
		$line = fgets($fp, 512);
		if (trim($line) == '') {
			break;
		}
		$headers .= trim($line)."\n";
		$x_pingback_header_offset = strpos(strtolower($headers), $x_pingback_str);
		if ($x_pingback_header_offset) {
			// We got it!
			preg_match('#x-pingback: (.+)#is', $headers, $matches);
			$pingback_server_url = trim($matches[1]);
			return $pingback_server_url;
		}
		if(strpos(strtolower($headers), 'content-type: ')) {
			preg_match('#content-type: (.+)#is', $headers, $matches);
			$content_type = trim($matches[1]);
		}
	}

	if (!preg_match('#(xml|xhtml|sgml)/#is', $content_type)) {
		// Not an (x)html, sgml, or xml page, no use going further
		return false;
	}

	// Send the GET request
	$request = "GET $path HTTP/1.1\r\nHost: $host\r\nUser-Agent: WordPress/$wp_version \r\n\r\n";
//	ob_end_flush();
	fputs($fp, $request);

	// Let's skip the header
	while (!feof($fp)) {
		$line = fgets($fp, 512);
		if (trim($line) == '') {
			break;
		}
	}

	while (!feof($fp)) {
		$line = fgets($fp, 1024);
		$contents .= trim($line);
		$pingback_link_offset_dquote = strpos($contents, $pingback_str_dquote);
		$pingback_link_offset_squote = strpos($contents, $pingback_str_squote);
		if ($pingback_link_offset_dquote || $pingback_link_offset_squote) {
			$quote = ($pingback_link_offset_dquote) ? '"' : '\'';
			$pingback_link_offset = ($quote=='"') ? $pingback_link_offset_dquote : $pingback_link_offset_squote;
			$pingback_href_pos = @strpos($contents, 'href=', $pingback_link_offset);
			$pingback_href_start = $pingback_href_pos+6;
			$pingback_href_end = @strpos($contents, $quote, $pingback_href_start);
			$pingback_server_url_len = $pingback_href_end - $pingback_href_start;
			$pingback_server_url = substr($contents, $pingback_href_start, $pingback_server_url_len);
			// We may find rel="pingback" but an incomplete pingback URI
			if ($pingback_server_url_len > 0) {
				// We got it!
				return $pingback_server_url;
			}
		}
		$byte_count += strlen($line);
		if ($byte_count > $timeout_bytes) {
			// It's no use going further, there probably isn't any pingback
			// server to find in this file. (Prevents loading large files.)
			return false;
		}
	}

	// We didn't find anything.
	return false;
}