8326458: Menu mnemonics don't toggle in Windows LAF when F10 is pressed

src/java.desktop/windows/classes/com/sun/java/swing/plaf/windows/WindowsMenuBarUI.java

@@ -147,9 +147,6 @@ public void actionPerformed(ActionEvent e) {
                 MenuSelectionManager msm =
                     MenuSelectionManager.defaultManager();
                 MenuElement[] selectedPath = msm.getSelectedPath();
-                //MenuElement[] path = new MenuElement[2];
-                //path[0] = (MenuElement)menuBar;
-                //path[1] = (MenuElement)menu;
                 if (selectedPath.length > 0 && (selectedPath[0] instanceof JMenuBar)) {
                     msm.clearSelectedPath();
                     WindowsLookAndFeel.setMnemonicHidden(true);

test/jdk/javax/swing/JMenu/TestMenuMnemonic.java

@@ -0,0 +1,133 @@
+/*
+ * Copyright (c) 2024, 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 8326458
+ * @key headful
+ * @requires (os.family == "windows")
+ * @modules java.desktop/com.sun.java.swing.plaf.windows
+ * @summary Verifies if menu mnemonics toggle between show or hide
+ *          on F10 press in windows LAF.
+ * @run main TestMenuMnemonic
+ */
+
+import java.awt.event.KeyEvent;
+import java.awt.Robot;
+import javax.swing.JFrame;
+import javax.swing.JMenu;
+import javax.swing.JMenuItem;
+import javax.swing.JMenuBar;
+import javax.swing.MenuElement;
+import javax.swing.MenuSelectionManager;
+import javax.swing.SwingUtilities;
+import javax.swing.UIManager;
+import com.sun.java.swing.plaf.windows.WindowsLookAndFeel;
+
+public class TestMenuMnemonic {
+
+    private static JFrame frame;
+    private static JMenuBar menuBar;
+    private static JMenu fileMenu;
+    private static JMenu editMenu;
+    private static JMenuItem item1;
+    private static JMenuItem item2;
+    private static int expectedMnemonicShowHideCount = 5;
+
+    public static void main(String[] args) throws Exception {
+        UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
+        Robot robot = new Robot();
+        robot.setAutoDelay(100);
+        int mnemonicHideCount = 0;
+        int mnemonicShowCount = 0;
+        try {
+            SwingUtilities.invokeAndWait(() -> {
+                createAndShowUI();
+            });
+
+            robot.waitForIdle();
+            robot.delay(1000);
+
+            for (int i = 0; i < 10; i++) {
+                robot.keyPress(KeyEvent.VK_F10);
+                robot.waitForIdle();
+                robot.delay(50);
+                robot.keyRelease(KeyEvent.VK_F10);
+                MenuSelectionManager msm =
+                        MenuSelectionManager.defaultManager();
+                MenuElement[] selectedPath = msm.getSelectedPath();
+                if (WindowsLookAndFeel.isMnemonicHidden()) {
+                    mnemonicHideCount++;
+                    // check if selection is cleared when mnemonics are hidden
+                    if (selectedPath.length != 0) {
+                        throw new RuntimeException("Menubar is active even after" +
+                                " mnemonics are hidden");
+                    }
+                } else {
+                    mnemonicShowCount++;
+                    if (selectedPath.length == 0 &&
+                        (selectedPath[0] != menuBar || selectedPath[1] != fileMenu)) {
+                        throw new RuntimeException("No Menu and Menubar is active when" +
+                                " mnemonics are shown");
+                    }
+                }
+            }
+            robot.waitForIdle();
+            robot.delay(1000);
+            if (mnemonicShowCount != expectedMnemonicShowHideCount
+                && mnemonicHideCount != expectedMnemonicShowHideCount) {
+                throw new RuntimeException("Mismatch in Mnemonic show/hide on F10 press");
+            }
+
+
+        } finally {
+            SwingUtilities.invokeAndWait(() -> {
+                if (frame != null) {
+                    frame.dispose();
+                }
+            });
+        }
+    }
+
+    private static void createAndShowUI() {
+        frame = new JFrame("Test Menu Mnemonic Show/Hide");
+        menuBar  = new JMenuBar();
+        fileMenu = new JMenu("File");
+        editMenu = new JMenu("Edit");
+        fileMenu.setMnemonic(KeyEvent.VK_F);
+        editMenu.setMnemonic(KeyEvent.VK_E);
+        item1 = new JMenuItem("Item 1");
+        item2 = new JMenuItem("Item 2");
+        fileMenu.add(item1);
+        fileMenu.add(item2);
+        menuBar.add(fileMenu);
+        menuBar.add(editMenu);
+        frame.setJMenuBar(menuBar);
+        frame.pack();
+        frame.setSize(250, 200);
+        frame.setLocationRelativeTo(null);
+        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        frame.setVisible(true);
+    }
+}
+