8301721: lookup.findSpecial fails on Object method call from interface

Reviewed-by: alanb

src/java.base/share/classes/java/lang/invoke/MethodHandles.java

@@ -4071,7 +4071,7 @@ return mh1;
 
             if (refKind == REF_invokeSpecial &&
                 refc != lookupClass() &&
-                !refc.isInterface() &&
+                !refc.isInterface() && !lookupClass().isInterface() &&
                 refc != lookupClass().getSuperclass() &&
                 refc.isAssignableFrom(lookupClass())) {
                 assert(!method.getName().equals(ConstantDescs.INIT_NAME));  // not this code path

test/jdk/java/lang/invoke/findSpecial/FindSpecialObjectMethod.java

@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 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 8301721
+ * @library /test/lib
+ * @run main FindSpecialObjectMethod
+ * @summary Test findSpecial on Object methods calling from a class or interface.
+ */
+
+import java.lang.invoke.MethodHandle;
+import java.lang.invoke.MethodHandles;
+import java.util.Objects;
+
+import static java.lang.invoke.MethodType.*;
+import static jdk.test.lib.Asserts.*;
+
+public class FindSpecialObjectMethod {
+    static class C {
+        public static Object test(C o) throws Throwable {
+            MethodHandles.Lookup lookup = MethodHandles.lookup();
+            MethodHandle mh = lookup.findSpecial(Object.class, "toString", methodType(String.class), C.class);
+            return mh.invoke(o);
+        }
+
+        public String toString() {
+            return "C";
+        }
+    }
+
+    interface I {
+        static Object test(I o) throws Throwable {
+            MethodHandles.Lookup lookup = MethodHandles.lookup();
+            MethodHandle mh = lookup.findSpecial(Object.class, "toString", methodType(String.class), I.class);
+            return mh.invoke(o);
+        }
+
+        static void noAccess() throws Throwable {
+            try {
+                MethodHandles.Lookup lookup = MethodHandles.lookup();
+                MethodHandle mh = lookup.findSpecial(String.class, "hashCode", methodType(int.class), I.class);
+                throw new RuntimeException("IllegalAccessException not thrown");
+            } catch (IllegalAccessException ex) {}
+        }
+    }
+
+    public static void main(String... args) throws Throwable {
+        // Object.toString can be called from invokespecial from within
+        // a special caller class C or interface I
+        C c = new C();
+        I i = new I() {};
+        assertEquals(C.test(c), Objects.toIdentityString(c));
+        assertEquals(I.test(i), Objects.toIdentityString(i));
+
+        // I has no access to methods in other class besides Object
+        I.noAccess();
+    }
+}