Version 1.6.2

dart/sdk/lib/_internal/compiler/implementation/inferrer/simple_types_inferrer.dart

 // 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.
 
 library simple_types_inferrer;
 
 import '../closure.dart' show ClosureClassMap, ClosureScope;
 import '../dart_types.dart'
     show DartType, InterfaceType, FunctionType, TypeKind;
 import '../elements/elements.dart';
@@ skipping 555 matching lines @@
       }
     }
 
     compiler.world.registerSideEffects(analyzedElement, sideEffects);
     assert(breaksFor.isEmpty);
     assert(continuesFor.isEmpty);
     return returnType;
   }
 
   T visitFunctionExpression(ast.FunctionExpression node) {
+    // We loose track of [this] in closures (see issue 20840). To be on
+    // the safe side, we mark [this] as exposed here. We could do better by
+    // analyzing the closure.
+    // TODO(herhut): Analyze whether closure exposes this.
+    isThisExposed = true;
     LocalFunctionElement element = elements.getFunctionDefinition(node);
     // We don't put the closure in the work queue of the
     // inferrer, because it will share information with its enclosing
     // method, like for example the types of local variables.
     LocalsHandler closureLocals = new LocalsHandler<T>.from(
         locals, node, useOtherTryBlock: false);
     SimpleTypeInferrerVisitor visitor = new SimpleTypeInferrerVisitor<T>(
         element, compiler, inferrer, closureLocals);
     visitor.run();
     inferrer.recordReturnType(element, visitor.returnType);
@@ skipping 701 matching lines @@
     }
 
     handlePlainAssignment(identifier, element, selector,
                           receiverType, currentType,
                           node.expression);
     return handleLoop(node, () {
       visit(node.body);
     });
   }
 }