Syntax error in i18n url function to add to AppHelper

[ghost]

This function to add to AppHelper doesn't work. It returns an synatx error:
"Parse error: syntax error, unexpected T_BOOLEAN_AND, expecting ')'"

    public function url($url = null, $full = false) {
        if (empty(is_array($url) && !array_key_exists('lang', $url)) {
            $url['lang'] = Configure::read('Config.language');
        }
        return parent::url($url, $full);
    }

The problem is the "&&" in the if clause...
For info, I'm using Cake 1.3.14 and PHP 5.3.8

[ghost]

When I use this version, it seems to work, the lang parameter is added, but I'm not sure it is the correct way...

    if (is_array($url) && !array_key_exists('lang', $url)) {
        $url['lang'] = Configure::read('Config.language');
    }
    return parent::url($url, $full);

[ghost]

I'm sorry, but your correction doesn't work!

Fatal error: Can't use function return value in write context

the problem is the test "empty(is_array($url))"