Breadcrumb - menu item + index item causes doubling of breadcrumbs

If there is a sitemenu pointing to a folder this will be included in the breadcrumb. If content based breadcrumbs are used, and the content matches to an index then an extra breadcrumb item will be created. An index should never generate a breadcrumb (the parent already covers that) but the breadcrumb provider only takes in account the path items. It needs to strip the index.