I’ve got a work around based on the following code that clears the reauth entry in the $_REQUEST object if the action entry is set to shibboleth.
function clear_reauth(){
if($_REQUEST['reauth'] && $_REQUEST['action'] == 'shibboleth'){
unset($_REQUEST['reauth']);
}
}
add_action( 'login_init', 'clear_reauth' );
I’m currently running it on a WordPress 4.0 MultiSite install and it’s running fine. The only issue I’ve encountered so far is a reauth issue.