Add a missing arity check for top-level methods in Dart_Invoke.

vm/dart_api_impl.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "include/dart_api.h"
 
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
 #include "vm/dart.h"
@@ skipping 2361 matching lines @@
     }
 
     // Finalize all classes if needed.
     if (finalize_classes) {
       const char* msg = CheckIsolateState(isolate);
       if (msg != NULL) {
         return Api::NewError(msg);
       }
     }
 
-    const Function& function =
-        Function::Handle(isolate, lib.LookupLocalFunction(function_name));
+    Function& function = Function::Handle(isolate);
+    function = lib.LookupLocalFunction(function_name);
+    // LookupLocalFunction does not check argument arity, so we do it here.
+    if (!function.IsNull() &&
+        !function.AreValidArgumentCounts(number_of_arguments, 0)) {
+      function = Function::null();
+    }
     if (function.IsNull()) {
       return Api::NewError("%s: did not find top-level function '%s'.",
                            CURRENT_FUNC,
                            function_name.ToCString());
     }
     return Api::NewHandle(
         isolate, DartEntry::InvokeStatic(function, dart_args, kNoArgNames));
 
   } else {
     return Api::NewError(
@@ skipping 1048 matching lines @@
       *buffer = NULL;
     }
     delete debug_region;
   } else {
     *buffer = NULL;
     *buffer_size = 0;
   }
 }
 
 }  // namespace dart