8016761: Lambda metafactory - incorrect type conversion of constructor method handle

Reviewed-by: jrose

src/share/classes/java/lang/invoke/InnerClassLambdaMetafactory.java

@@ -112,7 +112,9 @@ import java.security.PrivilegedAction;
         implMethodDesc = implMethodType.toMethodDescriptorString();
         Type implMethodAsmType = Type.getMethodType(implMethodDesc);
         implMethodArgumentTypes = implMethodAsmType.getArgumentTypes();
-        implMethodReturnType = implMethodAsmType.getReturnType();
+        implMethodReturnType = (implKind == MethodHandleInfo.REF_newInvokeSpecial)
+                ? Type.getObjectType(implMethodClassName)
+                : implMethodAsmType.getReturnType();
         constructorType = invokedType.changeReturnType(Void.TYPE);
         constructorDesc = constructorType.toMethodDescriptorString();
         lambdaClassName = targetClass.getName().replace('.', '/') + "$$Lambda$" + counter.incrementAndGet();

test/java/lang/invoke/lambda/LambdaConstructorMethodHandleUnbox.java

+/*
+ * Copyright (c) 2013, 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 8016761
+ * @summary Lambda metafactory: incorrect type conversion of constructor method handle
+ */
+
+public class LambdaConstructorMethodHandleUnbox {
+    interface IntFunction<X> {
+        int m(X x);
+    }
+
+    public static void main(String[] args) {
+       IntFunction<String> s = Integer::new;
+       if (s.m("2000") + s.m("13") != 2013) {
+           throw new RuntimeException("Lambda conversion failure");
+       }
+    }
+}