OG User Roles doesn't play nice with Relativity

I'm in the process of adapting the modules Relativity and Wikitools to allow each group to have their own hierarchy-based wiki, and I noticed that both Relativity and OG User Roles modify the URL for adding a node, in incompatible ways.

Relativity wants the URL to be like: node/add/$node-type/parent/$parent-nid
The group membership automatically adds the query parameter: gids[]=$group-nid
This will work so far, but OG User Roles wants to change it to: ognodeadd?type=$node-type&gids[]=$group-nid
which wipes out the parent node info.

Fortunately, Relativity also allows the parent node info to go as a query parameter, parent_node. To get Relativity and OG User Roles (and OG Forums as well, although I never tested this) to work together seemlessly, I only had to add a single piece of code to line 673 of "og_user_roles.module":

      //Modification to make it work with module "Relativity"
      if (module_exists('relativity')) {
      	if (arg(3) == 'parent' && is_numeric(arg(4))) {
          $query .= '&parent_node='.arg(4);
        }
        elseif (!empty($_GET['parent_node'])) {
      	  $query .= '&parent_node='.$_GET['parent_node'];
        }
      }

This goes after the code to allow the module to work with forums and before the call to "drupal_goto()".