6475361: Attempting to remove help menu from java.awt.MenuBar throws NullPointerException

Reviewed-by: azvegint, ant

src/share/classes/java/awt/MenuBar.java

 /*
- * Copyright (c) 1995, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1995, 2015, 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
@@ -181,7 +181,7 @@ public class MenuBar extends MenuComponent implements MenuContainer, Accessible
      * removed from the menu bar, and replaced with the specified menu.
      * @param m    the menu to be set as the help menu
      */
-    public void setHelpMenu(Menu m) {
+    public void setHelpMenu(final Menu m) {
         synchronized (getTreeLock()) {
             if (helpMenu == m) {
                 return;
@@ -189,11 +189,11 @@ public class MenuBar extends MenuComponent implements MenuContainer, Accessible
             if (helpMenu != null) {
                 remove(helpMenu);
             }
-            if (m.parent != this) {
-                add(m);
-            }
             helpMenu = m;
             if (m != null) {
+                if (m.parent != this) {
+                    add(m);
+                }
                 m.isHelpMenu = true;
                 m.parent = this;
                 MenuBarPeer peer = (MenuBarPeer)this.peer;
@@ -242,7 +242,7 @@ public class MenuBar extends MenuComponent implements MenuContainer, Accessible
      * @param        index   the position of the menu to be removed.
      * @see          java.awt.MenuBar#add(java.awt.Menu)
      */
-    public void remove(int index) {
+    public void remove(final int index) {
         synchronized (getTreeLock()) {
             Menu m = getMenu(index);
             menus.removeElementAt(index);
@@ -252,6 +252,10 @@ public class MenuBar extends MenuComponent implements MenuContainer, Accessible
                 m.parent = null;
                 peer.delMenu(index);
             }
+            if (helpMenu == m) {
+                helpMenu = null;
+                m.isHelpMenu = false;
+            }
         }
     }
 

test/java/awt/MenuBar/RemoveHelpMenu/RemoveHelpMenu.java

+/*
+ * Copyright (c) 2015, 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.
+ */
+
+import java.awt.Frame;
+import java.awt.Menu;
+import java.awt.MenuBar;
+
+/**
+ * @test
+ * @bug 6475361
+ * @author Sergey Bylokhov
+ */
+public final class RemoveHelpMenu {
+
+    public static void main(final String[] args) {
+        final Frame frame = new Frame("RemoveHelpMenu Test");
+        try {
+            frame.pack();
+            // peer exists
+            test1(getMenuBar(frame));
+            test2(getMenuBar(frame));
+            test3(getMenuBar(frame));
+            test4(getMenuBar(frame));
+        } finally {
+            frame.dispose();
+        }
+        // peer is null
+        test1(getMenuBar(frame));
+        test2(getMenuBar(frame));
+        test3(getMenuBar(frame));
+        test4(getMenuBar(frame));
+    }
+
+    private static MenuBar getMenuBar(final Frame frame) {
+        final MenuBar menuBar = new MenuBar();
+        frame.setMenuBar(menuBar);
+        return menuBar;
+    }
+
+    private static void checkHelpMenu(final Menu menu, final boolean expected) {
+        final boolean actual = menu.toString().contains("isHelpMenu=true");
+        if (actual != expected) {
+            throw new RuntimeException("Incorrect menu type");
+        }
+    }
+
+    private static void checkMenuCount(final MenuBar bar, final int expected) {
+        final int actual = bar.getMenuCount();
+        if (actual != expected) {
+            throw new RuntimeException("Incorrect menus count");
+        }
+    }
+
+    private static void checkCurrentMenu(final MenuBar bar, final Menu menu) {
+        if (bar.getHelpMenu() != menu) {
+            throw new RuntimeException("Wrong HelpMenu");
+        }
+    }
+
+    private static void test1(final MenuBar menuBar) {
+        checkCurrentMenu(menuBar, null);
+        checkMenuCount(menuBar, 0);
+    }
+
+    private static void test2(final MenuBar menuBar) {
+        final Menu helpMenu = new Menu("Help Menu");
+        menuBar.setHelpMenu(helpMenu);
+        checkCurrentMenu(menuBar, helpMenu);
+        checkMenuCount(menuBar, 1);
+        checkHelpMenu(helpMenu, true);
+
+        menuBar.remove(helpMenu);
+        checkCurrentMenu(menuBar, null);
+        checkMenuCount(menuBar, 0);
+        checkHelpMenu(helpMenu, false);
+    }
+
+    private static void test3(final MenuBar menuBar) {
+        final Menu helpMenu1 = new Menu("Help Menu1");
+        final Menu helpMenu2 = new Menu("Help Menu2");
+        menuBar.setHelpMenu(helpMenu1);
+        checkCurrentMenu(menuBar, helpMenu1);
+        checkMenuCount(menuBar, 1);
+        checkHelpMenu(helpMenu1, true);
+        checkHelpMenu(helpMenu2, false);
+
+        menuBar.setHelpMenu(helpMenu2);
+        checkCurrentMenu(menuBar, helpMenu2);
+        checkMenuCount(menuBar, 1);
+        checkHelpMenu(helpMenu1, false);
+        checkHelpMenu(helpMenu2, true);
+
+        menuBar.remove(helpMenu2);
+        checkCurrentMenu(menuBar, null);
+        checkMenuCount(menuBar, 0);
+        checkHelpMenu(helpMenu1, false);
+        checkHelpMenu(helpMenu2, false);
+    }
+
+    private static void test4(final MenuBar menuBar) {
+        final Menu helpMenu = new Menu("Help Menu");
+        menuBar.setHelpMenu(helpMenu);
+        checkCurrentMenu(menuBar, helpMenu);
+        checkMenuCount(menuBar, 1);
+        checkHelpMenu(helpMenu, true);
+
+        menuBar.setHelpMenu(null);
+        checkCurrentMenu(menuBar, null);
+        checkMenuCount(menuBar, 0);
+        checkHelpMenu(helpMenu, false);
+    }
+}
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