Form submission handler #4 for batch_test_chained_form().
function batch_test_chained_form_submit_4($form, &$form_state) {
batch_test_stack('submit handler 4');
batch_test_stack('value = ' . $form_state['values']['value']);
$form_state['values']['value']++;
batch_set(_batch_test_batch_3());
// This is the redirect that should prevail.
$form_state['redirect'] = 'batch-test/redirect';
}