Issue 3931. Visit children nodes safely.

compiler/java/com/google/dart/compiler/ast/DartFunctionExpression.java

Index: compiler/java/com/google/dart/compiler/ast/DartFunctionExpression.java
diff --git a/compiler/java/com/google/dart/compiler/ast/DartFunctionExpression.java b/compiler/java/com/google/dart/compiler/ast/DartFunctionExpression.java
index a26063af20280d9b5151404c311e0945e8b793f3..b8e028bf2869d59b17899155e75326bef2a8adbe 100644
--- a/compiler/java/com/google/dart/compiler/ast/DartFunctionExpression.java
+++ b/compiler/java/com/google/dart/compiler/ast/DartFunctionExpression.java
@@ -1,4 +1,4 @@
-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// 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.
 
@@ -61,10 +61,8 @@ public class DartFunctionExpression extends DartExpression {
 
   @Override
   public void visitChildren(ASTVisitor<?> visitor) {
-    if (name != null) {
-      name.accept(visitor);
-    }
-    function.accept(visitor);
+    safelyVisitChild(name, visitor);
+    safelyVisitChild(function, visitor);
   }
 
   @Override