Keep only InterfaceType(s) in resynthesized lists of interfaces and mixins.

pkg/analyzer/lib/src/dart/element/element.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.
 
 library analyzer.src.dart.element.element;
 
 import 'dart:collection';
 import 'dart:math' show min;
 
 import 'package:analyzer/dart/ast/ast.dart';
@@ skipping 725 matching lines @@
     }
     return false;
   }
 
   @override
   List<InterfaceType> get interfaces {
     if (_unlinkedClass != null && _interfaces == null) {
       ResynthesizerContext context = enclosingUnit.resynthesizerContext;
       _interfaces = _unlinkedClass.interfaces
           .map((EntityRef t) => context.resolveTypeRef(t, this))
+          .where((DartType type) => type is InterfaceType)
           .toList(growable: false);
     }
     return _interfaces ?? const <InterfaceType>[];
   }
 
   void set interfaces(List<InterfaceType> interfaces) {
     assert(_unlinkedClass == null);
     _interfaces = interfaces;
   }
 
@@ skipping 86 matching lines @@
     assert(_unlinkedClass == null);
     setModifier(Modifier.MIXIN_APPLICATION, isMixinApplication);
   }
 
   @override
   List<InterfaceType> get mixins {
     if (_unlinkedClass != null && _mixins == null) {
       ResynthesizerContext context = enclosingUnit.resynthesizerContext;
       _mixins = _unlinkedClass.mixins
           .map((EntityRef t) => context.resolveTypeRef(t, this))
+          .where((DartType type) => type is InterfaceType)
           .toList(growable: false);
     }
     return _mixins ?? const <InterfaceType>[];
   }
 
   void set mixins(List<InterfaceType> mixins) {
     assert(_unlinkedClass == null);
     _mixins = mixins;
   }
 
@@ skipping 10 matching lines @@
     if (_unlinkedClass != null) {
       return _unlinkedClass.nameOffset;
     }
     return super.nameOffset;
   }
 
   @override
   InterfaceType get supertype {
     if (_unlinkedClass != null && _supertype == null) {
       if (_unlinkedClass.supertype != null) {
         _supertype = enclosingUnit.resynthesizerContext

[Brian Wilkerson, 2016/09/09 18:26:28]

Does this need to check that the supertype is an InterfaceType?

[scheglov, 2016/09/09 18:44:47]

You are right, it does.
Done.

             .resolveTypeRef(_unlinkedClass.supertype, this);
       } else if (_unlinkedClass.hasNoSupertype) {
         return null;
       } else {
         _supertype = context.typeProvider.objectType;
       }
     }
     return _supertype;
   }
 
@@ skipping 7611 matching lines @@
 
   @override
   void visitElement(Element element) {
     int offset = element.nameOffset;
     if (offset != -1) {
       map[offset] = element;
     }
     super.visitElement(element);
   }
 }