Fix bug in our SSA optimizations: by giving an empty type to a box, we were assuming that anything …

sdk/lib/_internal/compiler/implementation/closure.dart

 // Copyright (c) 2012, 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 closureToClassMapper;
 
 import "elements/elements.dart";
 import "dart2jslib.dart";
 import "dart_types.dart";
 import "scanner/scannerlib.dart" show Token;
@@ skipping 131 matching lines @@
    * The most outer method this closure is declared into.
    */
   final Element methodElement;
 }
 
 // TODO(ahe): These classes continuously cause problems.  We need to
 // move these classes to elements/modelx.dart or see if we can find a
 // more general solution.
 class BoxElement extends ElementX {
   BoxElement(String name, Element enclosingElement)
-      : super(name, ElementKind.VARIABLE, enclosingElement);
+      : super(name, ElementKind.VARIABLE_LIST, enclosingElement);
 
   DartType computeType(Compiler compiler) => compiler.types.dynamicType;
 }
 
 // TODO(ngeoffray, ahe): These classes continuously cause problems.  We need to
 // move these classes to elements/modelx.dart or see if we can find a
 // more general solution.
 class BoxFieldElement extends ElementX {
   BoxFieldElement(String name,
                   this.variableElement,
@@ skipping 219 matching lines @@
         if (fromElement == updatedElement) {
           assert(freeVariableMapping[fromElement] == updatedElement);
           assert(Elements.isLocal(updatedElement)
                  || updatedElement.isTypeVariable());
           // The variable has not been boxed.
           fieldCaptures.add(updatedElement);
         } else {
           // A boxed element.
           freeVariableMapping[fromElement] = updatedElement;
           Element boxElement = updatedElement.enclosingElement;
-          assert(boxElement.kind == ElementKind.VARIABLE);
+          assert(boxElement is BoxElement);
           boxes.add(boxElement);
         }
       });
       ClassElement closureElement = data.closureClassElement;
       assert(closureElement != null ||
              (fieldCaptures.isEmpty && boxes.isEmpty));
       void addElement(Element element, String name) {
         Element fieldElement = new ClosureFieldElement(
             name, element, closureElement);
         closureElement.addMember(fieldElement, compiler);
@@ skipping 424 matching lines @@
   }
 
   visitTryStatement(TryStatement node) {
     // TODO(ngeoffray): implement finer grain state.
     bool oldInTryStatement = inTryStatement;
     inTryStatement = true;
     node.visitChildren(this);
     inTryStatement = oldInTryStatement;
   }
 }