--- a/src/share/classes/javax/swing/Popup.java	Sat Nov 13 19:31:00 2010 +0300
+++ b/src/share/classes/javax/swing/Popup.java	Mon Nov 15 19:50:09 2010 +0300
@@ -156,7 +156,8 @@
 
             component.setLocation(ownerX, ownerY);
             component.getContentPane().add(contents, BorderLayout.CENTER);
-            contents.invalidate();
+            component.invalidate();
+            component.validate();
             if(component.isVisible()) {
                 // Do not call pack() if window is not visible to
                 // avoid early native peer creation

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/javax/swing/JPopupMenu/6987844/bug6987844.java	Mon Nov 15 19:50:09 2010 +0300
@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 2010, 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 6987844
+ * @summary Incorrect width of JComboBox drop down
+ * @author Alexander Potochkin
+ * @run main bug6987844
+ */
+
+import sun.awt.SunToolkit;
+
+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.InputEvent;
+
+public class bug6987844 {
+    static JMenu menu1;
+    static JMenu menu2;
+
+    public static void main(String... args) throws Exception {
+        SunToolkit toolkit = (SunToolkit) Toolkit.getDefaultToolkit();
+        Robot robot = new Robot();
+        robot.setAutoDelay(200);
+
+        SwingUtilities.invokeAndWait(new Runnable() {
+            public void run() {
+                JFrame frame = new JFrame();
+                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+
+                JMenuBar bar = new JMenuBar();
+                menu1 = new JMenu("Menu1");
+                menu1.add(new JMenuItem("item"));
+                bar.add(menu1);
+                menu2 = new JMenu("Menu2");
+                menu2.add(new JMenuItem("item"));
+                menu2.add(new JMenuItem("item"));
+                bar.add(menu2);
+
+                frame.setJMenuBar(bar);
+                frame.pack();
+
+                frame.setVisible(true);
+            }
+        });
+        toolkit.realSync();
+        Point point1 = menu1.getLocationOnScreen();
+        Point point2 = menu2.getLocationOnScreen();
+
+        robot.mouseMove(point1.x + 1, point1.y + 1);
+        robot.mousePress(InputEvent.BUTTON1_MASK);
+        robot.mouseRelease(InputEvent.BUTTON1_MASK);
+
+        robot.mouseMove(point2.x + 1, point2.y + 1);
+        robot.mousePress(InputEvent.BUTTON1_MASK);
+        robot.mouseRelease(InputEvent.BUTTON1_MASK);
+        robot.mousePress(InputEvent.BUTTON1_MASK);
+        robot.mouseRelease(InputEvent.BUTTON1_MASK);
+
+        robot.mouseMove(point1.x + 1, point1.y + 1);
+        toolkit.realSync();
+
+        SwingUtilities.invokeAndWait(new Runnable() {
+            public void run() {
+                Dimension popupSize1 = menu1.getPopupMenu().getSize();
+                Dimension popupSize2 = menu2.getPopupMenu().getSize();
+                if (popupSize1.equals(popupSize2)) {
+                    throw new RuntimeException("First popup unexpedetly changed its size");
+                }
+            }
+        });
+    }
+}