Replacement of destination query impacts normal login

In the newest dev in fb_canvas.module > fb_canvas_url_outbound_alter() near line 510
$options['query'] = str_replace('destination=', 'fb_canvas_destination=', $options['query']);
affects the normal drupal login procedure: Drupal no longer jumps to the login destination (e.g. "node") but to your profile when not logged in via fb connect.

It may affect only older Drupal installation since mine is 6.6. but is reproducible every time with this version. So I let the report here for documentation purposes.

I circumvented this by moving the whole block into the if(fb_canvas_is_iframe)-block like this:

if (fb_canvas_is_iframe()) {
      if (!$options['absolute']) {
        // Could append all 'fb_sig' params to internal links.  But for now we rely on fb_canvas_process.
      }
      else {
        //dpm($options, "fb_canvas_url_outbound_alter($path)");
      }

      // Drupal has a habit of adding ?destination=... to some URLs.
      // And Facebook for no good reason screws up when you do that.
      if ($options['query']) {
        $options['query'] = str_replace('destination=', 'fb_canvas_destination=', $options['query']);
      }
    }