8306871: Open source more AWT Drag & Drop tests

Backport-of: b5a48277ab5b42c4b13db7ddb5418a17ada512ec

Author: Victor Rudometov

test/jdk/java/awt/event/HierarchyEvent/ObjectSourceTest.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2001, 2023, 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 4420658
+  @summary No ClassCastException should be thrown when getComponent()
+           is called on an event with a non-Component source.
+           The result should be null.
+  @run main ObjectSourceTest
+*/
+
+import java.awt.Component;
+import java.awt.Panel;
+import java.awt.event.HierarchyEvent;
+import java.lang.reflect.InvocationTargetException;
+
+
+public class ObjectSourceTest {
+    static Panel panel;
+
+    public static void main(String args[]) throws InterruptedException,
+            InvocationTargetException {
+        panel = new Panel();
+
+        HierarchyEvent he = new HierarchyEvent(panel, HierarchyEvent.ANCESTOR_MOVED,
+                panel, panel);
+        Object obj = new Object();
+        he.setSource(obj);
+
+        Component comp = he.getComponent();
+        if (comp != null) {
+            throw new RuntimeException("ObjectSourceTest failed.  comp != null");
+        }
+    }
+}