Fix issue 18865.

runtime/vm/object.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 "vm/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 13923 matching lines @@
     // Shortcut unnecessary handle allocation below.
     return true;
   }
   const intptr_t num_type_args = cls.NumTypeArguments();
   const intptr_t from_index = num_type_args - num_type_params;
   const TypeArguments& type_args = TypeArguments::Handle(isolate, arguments());
   const TypeArguments& other_type_args = TypeArguments::Handle(
       isolate, other_type.arguments());
   if (type_args.IsNull()) {
     // Ignore from_index.
-    return other_type_args.IsRaw(0, num_type_params);
+    return other_type_args.IsRaw(0, num_type_args);
   }
   if (other_type_args.IsNull()) {
     // Ignore from_index.
-    return type_args.IsRaw(0, num_type_params);
+    return type_args.IsRaw(0, num_type_args);
   }
   if (!type_args.IsSubvectorEquivalent(other_type_args,
                                        from_index,
                                        num_type_params)) {
     return false;
   }
 #ifdef DEBUG
   if (from_index > 0) {
     // Verify that the type arguments of the super class match, since they
     // depend solely on the type parameters that were just verified to match.
@@ skipping 4887 matching lines @@
   return tag_label.ToCString();
 }
 
 
 void UserTag::PrintJSONImpl(JSONStream* stream, bool ref) const {
   Instance::PrintJSONImpl(stream, ref);
 }
 
 
 }  // namespace dart