--- old/src/java.desktop/share/classes/java/awt/Component.java 2017-10-25 17:18:11.618622571 -0700 +++ new/src/java.desktop/share/classes/java/awt/Component.java 2017-10-25 17:18:11.466643479 -0700 @@ -2034,14 +2034,14 @@ * used by GlobalCursormanager to update cursor */ final Point getLocationOnScreen_NoTreeLock() { - + ComponentPeer peer = this.peer; if (peer != null && isShowing()) { if (peer instanceof LightweightPeer) { // lightweight component location needs to be translated // relative to a native component. Container host = getNativeContainer(); Point pt = host.peer.getLocationOnScreen(); - for(Component c = this; c != host; c = c.getParent()) { + for(Component c = this; c != host; c = c.getContainer()) { pt.x += c.x; pt.y += c.y; } --- /dev/null 2017-10-25 10:15:40.056618991 -0700 +++ new/test/jdk/java/awt/Component/GetScreenLocTest/ComponentGetLocationOnScreenNPETest.java 2017-10-25 17:18:11.918581302 -0700 @@ -0,0 +1,60 @@ +/* + * Copyright (c) 2002, 2017, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + */ + +/** + * @test + * @bug 8189204 + * @summary Possible NPE in Component::getLocationOnScreen() + * @run main ComponentGetLocationOnScreenNPETest + */ + +import javax.swing.*; +import java.awt.*; + +public class ComponentGetLocationOnScreenNPETest { + + private static Frame frame; + private static JPanel panel; + + public static void main(String[] args) throws Exception { + SwingUtilities.invokeAndWait(() -> { + frame = new Frame(); + JPanel parentPanel = new JPanel() { + @Override + public Container getParent() { + return new Frame(); + } + }; + frame.add(parentPanel); + panel = new JPanel(); + parentPanel.add(panel); + frame.setVisible(true); + }); + Robot robot = new Robot(); + robot.waitForIdle(); + robot.delay(200); + + SwingUtilities.invokeAndWait(panel::getLocationOnScreen); + SwingUtilities.invokeLater(frame::dispose); + } +}