title: Toolbar, onCreateOptionsMenu() returns false, 'up' navigation not working
body: <p>I'm using the new Toolbar on Lollipop (no support library). My activity has a list and if the list is empty, I don't want to show any options menu. My implementation looks like this:</p>
  
  <p>in onCreate():</p>
  
  <pre><code>setActionBar((Toolbar) findViewById(R.id.toolbar));
  getActionBar().setDisplayHomeAsUpEnabled(true);
  </code></pre>
  
  <p>And the menu method:</p>
  
  <pre><code>@Override
  public boolean onCreateOptionsMenu(Menu menu) {
      if (tasks.isEmpty()) {
          return false;
      }
  
      getMenuInflater().inflate(R.menu.menu_tasks, menu);
  
      return true;
  }
  </code></pre>
  
  <p>When the method inflates the menu and returns true, the 'up' navigation arrow works file; when the method returns false, the arrow is there, but clicking it doesn't do any thing. Is this some kind of an Android bug?</p>