Fix crash in certain cases (most obvious when selecting cart tabs in debugger).

src/gui/Dialog.cxx

@@ -422,10 +422,11 @@ void Dialog::drawDialog()
   // Draw outlines for focused widgets
   // Don't change focus, since this will trigger lost and received
   // focus events
-  if (_focusedWidget)
+  if(_focusedWidget)
   {
     _focusedWidget = Widget::setFocusForChain(this, getFocusList(),
       _focusedWidget, 0, false);
+    if(_focusedWidget)
       _focusedWidget->draw(); // make sure the highlight color is drawn initially
   }
 }