title: Xamarin.Forms Prism - Master not dismissing when selecting master page item
body: <p>In my Xamarin.Forms Prism app, I have a MasterDetailPage to handle navigation.  The MasterBehavior is set to Popover.</p>
  
  <pre><code>&lt;MasterDetailPage xmlns="http://xamarin.com/schemas/2014/forms"
                xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
                xmlns:views="clr-namespace:My.Mobile.Application.Views;assembly=My.Mobile.Application"
                x:Class="My.Mobile.Application.Frame.MainPage"
                MasterBehavior="Popover"&gt;
    &lt;MasterDetailPage.Master&gt;
      &lt;views:MasterPage x:Name="masterPage" /&gt;
    &lt;/MasterDetailPage.Master&gt;
  &lt;/MasterDetailPage&gt;
  </code></pre>
  
  <p>When the master is visible, if I select the menu item that is already being displayed as the detail item, the master does not automatically dismiss; I have to swipe the master closed if I want to stay on the same page.</p>
  
  <p>I tried manually registering to the ItemSelected event on my master's list view to be able to explicitly set IsPresented = false on the MasterDetailPage, but the event does not fire when selecting the item that is already being displayed:</p>
  
  <pre><code>public partial class MainPage : MasterDetailPage
  {
    public MainPage()
    {
      InitializeComponent();
      masterPage.ListView.ItemSelected += OnItemSelected;
    }
  
    private void OnItemSelected(object sender, SelectedItemChangedEventArgs e)
    {
      IsPresented = false;
    }
  }
  </code></pre>
  
  <p>This differs from the behavior of the Xamarin.Forms sample Master-Detail app, which closes the master when a selection is made (even if it is the same item that is already being displayed).</p>
  
  <p>Is this something that is being controlled by Prism?</p>