src/share/classes/javax/swing/SwingUtilities.java

@@ -354,11 +354,11 @@
                                       p.x,p.y,
                                       sourceEvent.getXOnScreen(),
                                       sourceEvent.getYOnScreen(),
                                       sourceEvent.getClickCount(),
                                       sourceEvent.isPopupTrigger(),
-                                      MouseEvent.NOBUTTON );
+                                      sourceEvent.getButton());
         }
         return newEvent;
     }