Allow empty handles to escape handle scopes.

src/api.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 519 matching lines @@
 
 i::Object** v8::HandleScope::RawClose(i::Object** value) {
   if (!ApiCheck(!is_closed_,
                 "v8::HandleScope::Close()",
                 "Local scope has already been closed")) {
     return 0;
   }
   LOG_API("CloseHandleScope");
 
   // Read the result before popping the handle block.
-  i::Object* result = *value;
+  i::Object* result = NULL;
+  if (value != NULL) {
+    result = *value;
+  }
   is_closed_ = true;
   i::HandleScope::Leave(&previous_);
 
+  if (value == NULL) {
+    return NULL;
+  }
+
   // Allocate a new handle on the previous handle block.
   i::Handle<i::Object> handle(result);
   return handle.location();
 }
 
 
 // --- N e a n d e r ---
 
 
 // A constructor cannot easily return an error value, therefore it is necessary
@@ skipping 3512 matching lines @@
 
 
 char* HandleScopeImplementer::Iterate(ObjectVisitor* v, char* storage) {
   HandleScopeImplementer* thread_local =
       reinterpret_cast<HandleScopeImplementer*>(storage);
   thread_local->IterateThis(v);
   return storage + ArchiveSpacePerThread();
 }
 
 } }  // namespace v8::internal