better property overriding field

frog/frogsh

 #!/usr/bin/env node
 //  ********** Library dart:core **************
 //  ********** Natives core.js **************
 // Copyright (c) 2011, 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.
 
 // TODO(jimhug): Completeness - see tests/corelib
 
 /** Implements extends for dart classes on javascript prototypes. */
@@ skipping 10926 matching lines @@
 PropertyMember.prototype.get$isProperty = function() {
   return true;
 }
 PropertyMember.prototype.get$returnType = function() {
   return $notnull_bool(this.getter == null) ? this.setter.returnType : this.getter.returnType;
 }
 PropertyMember.prototype.override = function(other) {
   if ($notnull_bool(!$notnull_bool(Member.prototype.override.call(this, other)))) return false;
   if ($notnull_bool(other.get$isProperty() || other.get$isField())) {
     if ($notnull_bool(other.get$isProperty())) this.addFromParent(other);
+    else this._overriddenField = other;
     return true;
   }
   else {
     world.error('property can only override field or property', this.get$span(), other.get$span());
     return false;
   }
 }
 PropertyMember.prototype.get_ = function(context, node, target, isDynamic) {
   if ($notnull_bool(this.getter == null)) {
+    if ($notnull_bool(this._overriddenField != null)) {
+      return this._overriddenField.get_(context, node, target, isDynamic);
+    }
     return target.invokeNoSuchMethod(context, ('get:' + this.name + ''), node);
   }
   return this.getter.invoke(context, node, target, Arguments.get$EMPTY(), false);
 }
 PropertyMember.prototype.set_ = function(context, node, target, value, isDynamic) {
+  if ($notnull_bool(this.setter == null)) {
+    if ($notnull_bool(this._overriddenField != null)) {
+      return this._overriddenField.set_(context, node, target, value, isDynamic);
+    }
+    return target.invokeNoSuchMethod(context, ('set:' + this.name + ''), node, new Arguments(null, [value]));
+  }
   return this.setter.invoke(context, node, target, new Arguments(null, [value]), isDynamic);
 }
 PropertyMember.prototype.addFromParent = function(parentMember) {
   if ($notnull_bool((parentMember instanceof ConcreteMember))) {
     parentMember = parentMember.baseMember;
   }
   if ($notnull_bool(this.getter == null)) this.getter = parentMember.getter;
   if ($notnull_bool(this.setter == null)) this.setter = parentMember.setter;
 }
 PropertyMember.prototype.resolve = function(inType) {
@@ skipping 7448 matching lines @@
       INTERFACE,
       LIBRARY,
       NATIVE,
       NEGATE,
       OPERATOR,
       SET,
       SOURCE,
       STATIC,
       TYPEDEF ]*/;
 main();