title: Restoring state in Android when using the 'up' button
body: <p>I am using <code>onSaveInstanceState()</code> to store an <code>ArrayList</code> member variable and restore it in the <code>onCreate()</code> method of the main activity.  This works in most circumstances such as rotating the screen etc. but if I open a new activity and use the 'up' button (not the back button) to navigate back to the main screen it seems to create a new main activity without passing the state bundle in <code>onCreate()</code>.</p>
  
  <p>I have confirmed that when the up button is pressed the <code>onDestroy()</code> method is called for the original instance of the main activity which makes no sense to me because I want it to resume the existing activity as if I had pressed the back button rather than create a new one.</p>
  
  <p>Is there a way I can force the new activity to restore the old one or just resume the existing activity?</p>