- Do not attempt to set parameter types if they

runtime/vm/class_finalizer.cc

 // Copyright (c) 2013, 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/class_finalizer.h"
 
 #include "vm/code_generator.h"
 #include "vm/flags.h"
 #include "vm/heap.h"
 #include "vm/isolate.h"
@@ skipping 1128 matching lines @@
   }
 }
 
 
 void ClassFinalizer::ResolveAndFinalizeSignature(const Class& cls,
                                                  const Function& function) {
   // Resolve result type.
   AbstractType& type = AbstractType::Handle(function.result_type());
   // It is not a compile time error if this name does not resolve to a class or
   // interface.
-  type = FinalizeType(cls, type, kCanonicalize);
+  AbstractType& finalized_type =
+      AbstractType::Handle(FinalizeType(cls, type, kCanonicalize));
   // The result type may be malformed or malbounded.
-  function.set_result_type(type);
+  if (type.raw() != finalized_type.raw()) {
+    function.set_result_type(type);
+  }
   // Resolve formal parameter types.
   const intptr_t num_parameters = function.NumParameters();
   for (intptr_t i = 0; i < num_parameters; i++) {
     type = function.ParameterTypeAt(i);
-    type = FinalizeType(cls, type, kCanonicalize);
+    finalized_type = FinalizeType(cls, type, kCanonicalize);
     // The parameter type may be malformed or malbounded.
-    function.SetParameterTypeAt(i, type);
+    if (type.raw() != finalized_type.raw()) {
+      function.SetParameterTypeAt(i, type);
+    }
   }
 }
 
 
 // Check if an instance field, getter, or method of same name exists
 // in any super class.
 static RawClass* FindSuperOwnerOfInstanceMember(const Class& cls,
                                                 const String& name,
                                                 const String& getter_name) {
   Class& super_class = Class::Handle();
@@ skipping 1904 matching lines @@
   ASSERT(fields_array.Length() == ByteBuffer::NumberOfFields());
   field ^= fields_array.At(0);
   ASSERT(field.Offset() == ByteBuffer::data_offset());
   name ^= field.name();
   expected_name ^= String::New("_data");
   ASSERT(String::EqualsIgnoringPrivateKey(name, expected_name));
 #endif
 }
 
 }  // namespace dart