deselect the current selection when the user clicks outside of any item

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@37800 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/listctrl.cpp

@@ -2949,7 +2949,8 @@ void wxListMainWindow::OnMouse( wxMouseEvent &event )
 
     if ( !hitResult )
     {
-        // outside of any item
+        // outside of any item, reset the selection and bail out
+        HighlightAll(false);
         return;
     }