First tab hide/show

I have a strange behaviour (I think it is a bug) in TabSheet.
We nned to dynamically hide and show different tabs, when the first tab is hidden we are not able to set it visible again.

here is the simplest test to show the problem:

public class TabbugUI extends UI implements Button.ClickListener {

@WebServlet(value = "/*", asyncSupported = true)
@VaadinServletConfiguration(productionMode = false, ui = TabbugUI.class)
public static class Servlet extends VaadinServlet {

Tab _t;

protected void init(VaadinRequest request) {
    TabSheet p = new TabSheet();
    _t = p.addTab(new Label("a"), "a");
    p.addTab(new Label("b"), "b");
    p.addTab(new Label("c"), "c");
    setContent(new VerticalLayout(p, new Button("switch", this)));

public void buttonClick(ClickEvent event) {


once the button is pressed (and the “a” tab is hidden), the tab will never appear. The code works for the other tabs.

Seems like a bug since the style “display: none” is never removed for the first tab, please file a ticket at