Fix issue number 398: replacing a constant function on a clone.

src/objects.cc

Index: src/objects.cc
===================================================================
--- src/objects.cc	(revision 2377)
+++ src/objects.cc	(working copy)
@@ -1865,7 +1865,7 @@
       if (value == result->GetConstantFunction()) return value;
       // Preserve the attributes of this existing property.
       attributes = result->GetAttributes();
-      return ConvertDescriptorToFieldAndMapTransition(name, value, attributes);
+      return ConvertDescriptorToField(name, value, attributes);
     case CALLBACKS:
       return SetPropertyWithCallback(result->GetCallbackObject(),
                                      name,
@@ -1947,7 +1947,7 @@
       if (value == result->GetConstantFunction()) return value;
       // Preserve the attributes of this existing property.
       attributes = result->GetAttributes();
-      return ConvertDescriptorToFieldAndMapTransition(name, value, attributes);
+      return ConvertDescriptorToField(name, value, attributes);
     case CALLBACKS:
     case INTERCEPTOR:
       // Override callback in clone