Make formatting error message side-effect-free.

src/runtime.cc

Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index fb40d5e73e3c3dd85b15165c88487f6d893cbd5f..3129c930a2e2fcc751271f59865e2c81186f301c 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -4238,6 +4238,27 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DefineOrRedefineDataProperty) {
 }
 
 
+// Return property without being observable by accessors or interceptors.
+RUNTIME_FUNCTION(MaybeObject*, Runtime_GetDataProperty) {
+  ASSERT(args.length() == 2);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, object, 0);
+  CONVERT_ARG_HANDLE_CHECKED(String, key, 1);
+  LookupResult lookup(isolate);
+  object->LookupRealNamedProperty(*key, &lookup);
+  if (!lookup.IsProperty()) return isolate->heap()->undefined_value();

[Sven Panne, 2012/11/12 10:14:00]

With the change below, this can change to ...!lookup.IsFound()...

+  switch (lookup.type()) {
+    case NORMAL:
+      return lookup.holder()->GetNormalizedProperty(&lookup);
+    case FIELD:
+      return lookup.holder()->FastPropertyAt(lookup.GetFieldIndex());
+    case CONSTANT_FUNCTION:
+      return lookup.GetConstantFunction();
+    default:

[Sven Panne, 2012/11/12 10:14:00]

Please explicitly list all PropertyTypes. We should never use a default case for
enums, because it makes it impossible to find the places which should change
when the corresponding enum changes in an automatic way.

+      return isolate->heap()->undefined_value();
+  }
+}
+
+
 MaybeObject* Runtime::SetObjectProperty(Isolate* isolate,
                                         Handle<Object> object,
                                         Handle<Object> key,