Check field type when evaluating initializing formals.

pkg/analyzer/lib/src/generated/constant.dart

 // Copyright (c) 2014, 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.
 
 // This code was auto-generated, is not intended to be edited, and is subject to
 // significant change. Please see the README file for more information.
 
 library engine.constant;
 
 import 'dart:collection';
@@ skipping 715 matching lines @@
         }
       }
       if (argumentValue != null) {
         if (!argumentValue.isNull && !argumentValue.type.isSubtypeOf(parameter.type)) {
           errorReporter.reportErrorForNode(
               CheckedModeCompileTimeErrorCode.CONST_CONSTRUCTOR_PARAM_TYPE_MISMATCH,
               errorTarget,
               [argumentValue.type, parameter.type]);
         }
         if (baseParameter.isInitializingFormal) {
-          FieldElement field = (baseParameter as FieldFormalParameterElement).field;
+          FieldElement field = (parameter as FieldFormalParameterElement).field;
           if (field != null) {
+            DartType fieldType = field.type;
+            if (fieldType != parameter.type) {
+              // We've already checked that the argument can be assigned to the
+              // parameter; we also need to check that it can be assigned to
+              // the field.
+              if (!argumentValue.isNull &&
+                  !argumentValue.type.isSubtypeOf(fieldType)) {
+                errorReporter.reportErrorForNode(
+                    CheckedModeCompileTimeErrorCode.CONST_CONSTRUCTOR_PARAM_TYPE_MISMATCH,
+                    errorTarget,
+                    [argumentValue.type, fieldType]);
+              }
+            }
             String fieldName = field.name;
             fieldMap[fieldName] = argumentValue;
           }
         } else {
           String name = baseParameter.name;
           parameterMap[name] = argumentValue;
         }
       }
     }
     ConstantVisitor initializerVisitor = new ConstantVisitor.con2(typeProvider, parameterMap, errorReporter);
@@ skipping 3866 matching lines @@
 
   @override
   String get typeName => "Type";
 
   @override
   int get hashCode => _element == null ? 0 : _element.hashCode;
 
   @override
   String toString() => _element == null ? "-unknown-" : _element.name;
 }