Condition is useless here. At worst you'll get an empty string.
My advise would be to set it directly in the blocks above:

```php
            // In some cases $moduleRedirectUri can already contain $redirectURI (including the siteaccess).
            if ( !empty( $redirectURI ) && strpos( $moduleRedirectUri, $redirectURI ) === 0 )
            {
                $redirectURI = $moduleRedirectUri . eZSys::queryString();
            }
            else
            {
                $redirectURI .= $moduleRedirectUri . eZSys::queryString();
            }
```