--- old/src/java.desktop/share/classes/javax/swing/plaf/basic/BasicComboPopup.java	2017-11-21 14:24:16.000000000 -0800
+++ new/src/java.desktop/share/classes/javax/swing/plaf/basic/BasicComboPopup.java	2017-11-21 14:24:16.000000000 -0800
@@ -538,7 +538,7 @@
                     Toolkit toolkit = Toolkit.getDefaultToolkit();
                     MouseEvent newEvent = new MouseEvent(
                                        (Component)e.getSource(), e.getID(), e.getWhen(),
-                                       e.getModifiers() ^ toolkit.getMenuShortcutKeyMask(),
+                                       e.getModifiersEx() ^ toolkit.getMenuShortcutKeyMaskEx(),
                                        e.getX(), e.getY(),
                                        e.getXOnScreen(), e.getYOnScreen(),
                                        e.getClickCount(),