6681958: Maximization state of JInternalFrames is corrupted by WindowsDesktopManager

Reviewed-by: tr, kizune

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2025, 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
@@ -80,10 +80,13 @@ public final class WindowsDesktopManager extends DefaultDesktopManager
                         if (f.isMaximizable()) {
                             if (!f.isMaximum()) {
                                 f.setMaximum(true);
-                            } else if (f.isMaximum() && f.isIcon()) {
-                                f.setIcon(false);
                             } else {
-                                f.setMaximum(false);
+                                // If frame being activated is set to maximised
+                                // and iconified, let it be maximised
+                                // else remain non-maximised
+                                if (f.isIcon()) {
+                                    f.setIcon(false);
+                                }
                             }
                         }
                     }

test/jdk/javax/swing/JInternalFrame/JIFMaximizedTrfAttribute.java

@@ -0,0 +1,100 @@
+/*
+ * Copyright (c) 2025, 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 6681958
+ * @summary Verifies Maximization state of JInternalFrames is
+ *          not corrupted by WindowsDesktopManager
+ * @requires (os.family == "windows")
+ * @library /java/awt/regtesthelpers
+ * @build PassFailJFrame
+ * @run main/manual JIFMaximizedTrfAttribute
+ */
+
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+import java.awt.BorderLayout;
+
+import javax.swing.JButton;
+import javax.swing.JDesktopPane;
+import javax.swing.JFrame;
+import javax.swing.JInternalFrame;
+import javax.swing.UIManager;
+
+import java.beans.PropertyVetoException;
+
+public class JIFMaximizedTrfAttribute {
+
+    static final String INSTRUCTIONS = """
+        A maximised JInternalFrame would be shown with a
+        button "open another internal frame".
+        Press the button on the internal frame.
+        A second internal frame is created and opened.
+        If second internal frame is maximized,
+        press Pass else press Fail.""";
+
+    public static void main(String[] args) throws Exception {
+        // Set Windows L&F
+        UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
+        PassFailJFrame.builder()
+                .title("Test Instructions")
+                .instructions(INSTRUCTIONS)
+                .columns(50)
+                .testUI(JIFMaximizedTrfAttribute::createUI)
+                .position(PassFailJFrame.Position.TOP_LEFT_CORNER)
+                .build()
+                .awaitAndCheck();
+    }
+
+    static JFrame createUI() {
+
+        final JDesktopPane pane = new JDesktopPane();
+        final JInternalFrame internal = new JInternalFrame("the first internal frame", true, true, true, true);
+        pane.add(internal);
+        internal.setBounds(0, 0, 200, 100);
+        try {
+            internal.setMaximum(true);
+        } catch (PropertyVetoException e) { }
+        internal.setVisible(true);
+        JButton button = new JButton("open another internal frame");
+        button.addActionListener(new ActionListener() {
+            public void actionPerformed(ActionEvent evt) {
+                final JInternalFrame internal2 = new JInternalFrame("another one", true, true, true, true);
+                pane.add(internal2);
+                internal2.setBounds(250, 150, 200, 100);
+                try {
+                    internal2.setMaximum(true);
+                } catch (PropertyVetoException e) {}
+                internal2.setVisible(true);
+            }
+        });
+        internal.add(button, BorderLayout.SOUTH);
+
+        JFrame f = new JFrame("JIFMaximizedTrfAttribute");
+        f.add(pane, BorderLayout.CENTER);
+        f.setSize(800, 600);
+        f.setLocationRelativeTo(null);
+        return f;
+    }
+}