JBR-3024 Popups are shown with 1x1 size sometimes

test case only

(cherry picked part of commit ee298f5287)

with fix for JBR-5300 Change source code and test files to use GPL license

(cherry picked from commit b7d165e486)

test/jdk/jb/java/awt/Window/PopupSizeOnOpeningTest.java

@@ -0,0 +1,103 @@
+/*
+ * Copyright 2021-2023 JetBrains s.r.o.
+ * 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 javax.swing.*;
+import java.awt.*;
+import java.awt.event.*;
+
+/**
+ * @test
+ * @summary Regression test for JBR-3024 Popups are shown with 1x1 size sometimes
+ * @key headful
+ */
+
+public class PopupSizeOnOpeningTest {
+    private static Robot robot;
+    private static JFrame frame;
+    private static JLabel clickPlace;
+    private static JWindow popup;
+
+    public static void main(String[] args) throws Exception {
+        robot = new Robot();
+        try {
+            SwingUtilities.invokeAndWait(PopupSizeOnOpeningTest::initUI);
+            robot.delay(3000);
+            clickAt(clickPlace); // make sure frame is focused
+
+            for (int i = 0; i < 10; i++) {
+                robot.delay(1000);
+                pressAndReleaseSpace(); // open popup
+                robot.delay(1000);
+                Dimension size = popup.getSize();
+                if (size.width <= 1 || size.height <= 1) {
+                    throw new RuntimeException("Unexpected popup size: " + size);
+                }
+                pressAndReleaseSpace(); // close popup
+            }
+        } finally {
+            SwingUtilities.invokeAndWait(PopupSizeOnOpeningTest::disposeUI);
+        }
+    }
+
+    private static void initUI() {
+        frame = new JFrame("PopupSizeOnOpeningTest");
+        frame.setLayout(new FlowLayout());
+        frame.add(clickPlace = new JLabel("Click here"));
+        JButton openButton = new JButton("Open popup");
+        openButton.addActionListener(e -> {
+            popup = new JWindow(frame);
+            JButton closeButton = new JButton("Close popup");
+            closeButton.addActionListener(ev -> {
+                popup.dispose();
+                popup = null;
+            });
+            popup.add(closeButton);
+            popup.pack();
+            popup.setLocationRelativeTo(frame);
+            popup.setVisible(true);
+        });
+        frame.add(openButton);
+        frame.pack();
+        frame.setVisible(true);
+    }
+
+    private static void disposeUI() {
+        if (frame != null) frame.dispose();
+    }
+
+    private static void pressAndReleaseSpace() {
+        robot.keyPress(KeyEvent.VK_SPACE);
+        robot.keyRelease(KeyEvent.VK_SPACE);
+    }
+
+    private static void clickAt(int x, int y) {
+        robot.mouseMove(x, y);
+        robot.mousePress(InputEvent.BUTTON1_DOWN_MASK);
+        robot.mouseRelease(InputEvent.BUTTON1_DOWN_MASK);
+    }
+
+    private static void clickAt(Component component) {
+        Point location = component.getLocationOnScreen();
+        clickAt(location.x + component.getWidth() / 2, location.y + component.getHeight() / 2);
+    }
+}