Issue 163: IsSelected vs IsActive behavior changed from 3.x to 4.1/4.2

Fix: re-integrated code from older version (removed in rev 4927453)

source/Components/AvalonDock/Controls/LayoutDocumentPaneControl.cs

@@ -68,6 +68,19 @@ internal LayoutDocumentPaneControl(LayoutDocumentPane model, bool isVirtualizing
 
 		#region Overrides
 
+		/// <summary>
+		/// Invoked when an unhandled SelectionChanged routed event is raised on this element. Implement this method
+		/// to add class handling for this event.
+		/// </summary>
+		/// <param name="e">The <see cref="SelectionChangedEventArgs"/> that contains the event data.
+		/// The event reports that the selection changed.</param>
+		protected override void OnSelectionChanged(SelectionChangedEventArgs e)
+		{
+			base.OnSelectionChanged(e);
+			if (_model.SelectedContent != null)
+				_model.SelectedContent.IsActive = true;
+		}
+
 		/// <summary>
 		/// Invoked when an unhandled <see cref="System.Windows.UIElement.MouseLeftButtonDown"/> routed
 		/// event is raised on this element. Implement this method to add class handling