Rearranging the deck chairs on the titanic.

pkg/compiler/lib/src/ssa/locals_handler.dart

 // Copyright (c) 2016, 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.
 
 import '../closure.dart';
 import '../common.dart';
 import '../elements/elements.dart';
 import '../elements/entities.dart';
 import '../elements/types.dart';
 import '../io/source_information.dart';
@@ skipping 205 matching lines @@
         }
       }
       HInstruction parameter = builder.addParameter(local, typeMask);
       builder.parameters[local] = parameter;
       directLocals[local] = parameter;
     });
 
     enterScope(scopeData,
         forGenerativeConstructorBody: isGenerativeConstructorBody);
 
-    // If the freeVariableMapping is not empty, then this function was a
-    // nested closure that captures variables. Redirect the captured
-    // variables to fields in the closure.
-    closureData.forEachFreeVariable((Local from, FieldEntity to) {
-      redirectElement(from, to);
-    });
     if (closureData.isClosure) {
+      // If the freeVariableMapping is not empty, then this function was a
+      // nested closure that captures variables. Redirect the captured
+      // variables to fields in the closure.
+      closureData.forEachFreeVariable((Local from, FieldEntity to) {
+        redirectElement(from, to);
+      });
       // Inside closure redirect references to itself to [:this:].
       HThis thisInstruction =
           new HThis(closureData.thisLocal, commonMasks.nonNullType);
       builder.graph.thisInstruction = thisInstruction;
       builder.graph.entry.addAtEntry(thisInstruction);
       updateLocal(closureData.closureEntity, thisInstruction);
     } else if (element.isInstanceMember) {
       // Once closures have been mapped to classes their instance members might
       // not have any thisElement if the closure was created inside a static
       // context.
@@ skipping 427 matching lines @@
   final MemberEntity memberContext;
 
   // Avoid slow Object.hashCode.
   final int hashCode = _nextHashCode = (_nextHashCode + 1).toUnsigned(30);
   static int _nextHashCode = 0;
 
   SyntheticLocal(this.name, this.executableContext, this.memberContext);
 
   toString() => 'SyntheticLocal($name)';
 }