8019184: MethodHandles.catchException() fails when methods have 8 args + varargs

Reviewed-by: jrose

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

@@ -747,7 +747,8 @@ import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
             GuardWithCatch gguard = new GuardWithCatch(gtarget, exType, gcatcher);
             if (gtarget == null || gcatcher == null)  throw new InternalError();
             MethodHandle ginvoker = GuardWithCatch.VARARGS_INVOKE.bindReceiver(gguard);
-            return makeCollectArguments(ginvoker, ValueConversions.varargsArray(nargs), 0, false);
+            MethodHandle gcollect = makeCollectArguments(ginvoker, ValueConversions.varargsArray(nargs), 0, false);
+            return makePairwiseConvert(gcollect, type, 2);
         }
     }
 

test/java/lang/invoke/TestCatchExceptionWithVarargs.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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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 8019184
+ * @summary MethodHandles.catchException() fails when methods have 8 args + varargs
+ */
+
+import java.util.*;
+import java.lang.invoke.*;
+
+public class TestCatchExceptionWithVarargs {
+
+    private static final Class<?> CLASS = TestCatchExceptionWithVarargs.class;
+    private static final int MAX_MH_ARITY = 254;
+
+    public static MethodHandle target;
+    public static MethodHandle handler;
+
+    private static Object firstArg;
+
+    static class MyException extends Exception {
+    }
+
+    public static Object target(Object... a) throws Exception {
+        if (a[0] != firstArg) {
+            throw new AssertionError("first argument different than expected: " + a[0] + " != " + firstArg);
+        }
+        throw new MyException();
+    }
+
+    public static Object handler(Object... a) {
+        if (a[0] != firstArg) {
+            throw new AssertionError("first argument different than expected: " + a[0] + " != " + firstArg);
+        }
+        return a[0];
+    }
+
+    static {
+        try {
+            MethodType mtype = MethodType.methodType(Object.class, Object[].class);
+            target = MethodHandles.lookup().findStatic(CLASS, "target", mtype);
+            handler = MethodHandles.lookup().findStatic(CLASS, "handler", mtype);
+        } catch (Exception e) {
+            throw new AssertionError(e);
+        }
+    }
+
+    public static void main(String[] args) throws Throwable {
+        List<Class<?>> ptypes = new LinkedList<>();
+        ptypes.add(Object[].class);
+
+        // We use MAX_MH_ARITY - 1 here to account for the Object[] argument.
+        for (int i = 1; i < MAX_MH_ARITY - 1; i++) {
+            ptypes.add(0, Object.class);
+
+            MethodHandle targetWithArgs = target.asType(MethodType.methodType(Object.class, ptypes));
+            MethodHandle handlerWithArgs = handler.asType(MethodType.methodType(Object.class, ptypes));
+            handlerWithArgs = MethodHandles.dropArguments(handlerWithArgs, 0, MyException.class);
+
+            MethodHandle gwc1 = MethodHandles.catchException(targetWithArgs, MyException.class, handlerWithArgs);
+
+            // The next line throws an IllegalArgumentException if there is a bug.
+            MethodHandle gwc2 = MethodHandles.catchException(gwc1, MyException.class, handlerWithArgs);
+
+            // This is only to verify that the method handles can actually be invoked and do the right thing.
+            firstArg = new Object();
+            Object o = gwc2.asSpreader(Object[].class, ptypes.size() - 1).invoke(firstArg, new Object[i]);
+            if (o != firstArg) {
+                throw new AssertionError("return value different than expected: " + o + " != " + firstArg);
+            }
+        }
+    }
+}