8159696: java.beans.MethodRef#get throws NullPointerException

Reviewed-by: alexsch

src/share/classes/java/beans/MethodRef.java

 /*
- * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2016, 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
@@ -64,10 +64,9 @@ final class MethodRef {
                 this.signature = null;
                 this.methodRef = null;
                 this.typeRef = null;
+                return null;
             }
-            else {
-                this.methodRef = new SoftReference<>(method);
-            }
+            this.methodRef = new SoftReference<>(method);
         }
         return isPackageAccessible(method.getDeclaringClass()) ? method : null;
     }

test/java/beans/Introspector/8159696/UnloadClassBeanInfo.java

+/*
+ * Copyright (c) 2016, 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.beans.BeanInfo;
+import java.beans.Introspector;
+import java.beans.MethodDescriptor;
+import java.io.File;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.nio.file.StandardCopyOption;
+import java.util.Arrays;
+
+/**
+ * @test
+ * @bug 8159696
+ * @library /javax/swing/regtesthelpers
+ * @compile ./stub/Stub.java
+ * @run main/othervm -mx32M UnloadClassBeanInfo
+ */
+public class UnloadClassBeanInfo {
+
+    private static URLClassLoader loader;
+
+    public static void main(final String[] args) throws Exception {
+        Class cl = getStub();
+        System.out.println("cl.getClassLoader() = " + cl.getClassLoader());
+        final BeanInfo beanInfo = Introspector.getBeanInfo(cl, Object.class);
+        MethodDescriptor[] mds = beanInfo.getMethodDescriptors();
+        System.out.println("mds = " + Arrays.toString(mds));
+        loader.close();
+        loader=null;
+        cl=null;
+        Util.generateOOME();
+        mds = beanInfo.getMethodDescriptors();
+        System.out.println("mds = " + Arrays.toString(mds));
+    }
+
+    /**
+     * The Stub class is compiled by jtreg, but we want to move it so it is not
+     * on the application classpath. We want to load it through a separate
+     * classloader.
+     */
+    static Class<?> getStub() throws Exception {
+        final String testclasses = System.getProperty("test.classes");
+        final File subdir = new File(testclasses, "stub");
+        subdir.mkdir();
+
+        final Path src = Paths.get(testclasses, "Stub.class");
+        final Path dest = subdir.toPath().resolve("Stub.class");
+        Files.move(src, dest, StandardCopyOption.REPLACE_EXISTING);
+
+        loader = new URLClassLoader(new URL[]{subdir.toURL()});
+        return Class.forName("Stub", true, loader);
+    }
+}

test/java/beans/Introspector/8159696/stub/Stub.java

+/*
+ * Copyright (c) 2016, 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.
+ */
+
+public final class Stub {
+
+    public void test() {
+
+    }
+}