function test() {
  var tabCount = gBrowser.tabs.length;
  gBrowser.selectedBrowser.focus();
  window.browserDOMWindow.openURI(
    makeURI("about:blank"),
    null,
    Ci.nsIBrowserDOMWindow.OPEN_NEWTAB,
    Ci.nsIBrowserDOMWindow.OPEN_EXTERNAL,
    Services.scriptSecurityManager.getSystemPrincipal()
  );
  is(
    gBrowser.tabs.length,
    tabCount + 1,
    "'--new-tab about:blank' opens a new tab"
  );
  is(
    gBrowser.selectedTab,
    gBrowser.tabs[tabCount],
    "'--new-tab about:blank' selects the new tab"
  );
  is(
    document.activeElement,
    gURLBar.inputField,
    "'--new-tab about:blank' focuses the location bar"
  );
  gBrowser.removeCurrentTab();
}