[drupal-devel] node_access_where_sql()

I'm debugging an issue in the project module on Drupal cvs. Most node queries use the node_access_where_sql() function like so. "SELECT foo FROM bar WHERE " . node_access_where_sql() . " AND criteria = true" However, the first test in the function returns nothing which will obviously result in an invalid query. Shouldn't the function return a value of "0" or something so that queries will always be valid? http://drupaldocs.org/api/head/function/node_access_where_sql