Make Object::GetIdentityHash() never return 0....

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 2054 matching lines @@
   ON_BAILOUT("v8::Object::GetIdentityHash()", return 0);
   ENTER_V8;
   i::Handle<i::JSObject> self = Utils::OpenHandle(this);
   i::Handle<i::Object> hidden_props(i::GetHiddenProperties(self, true));
   i::Handle<i::Object> hash_symbol = i::Factory::identity_hash_symbol();
   i::Handle<i::Object> hash = i::GetProperty(hidden_props, hash_symbol);
   int hash_value;
   if (hash->IsSmi()) {
     hash_value = i::Smi::cast(*hash)->value();
   } else {
-    hash_value = random() & i::Smi::kMaxValue;  // Limit range to fit a smi.
+    int attempts = 0;
+    do {
+      hash_value = random() & i::Smi::kMaxValue;  // Limit range to fit a smi.

[Dean McNamee, 2009/04/29 09:14:52]

Just to be annoying, we probably shouldn't be using random() (it's not thread
safe, etc).

+      attempts++;
+    } while (hash_value == 0 && attempts < 30);
+    hash_value = hash_value != 0 ? hash_value : 1;  // never return 0
     i::SetProperty(hidden_props,
                    hash_symbol,
                    i::Handle<i::Object>(i::Smi::FromInt(hash_value)),
                    static_cast<PropertyAttributes>(None));
   }
   return hash_value;
 }
 
 
 bool v8::Object::SetHiddenValue(v8::Handle<v8::String> key,
@@ skipping 1301 matching lines @@
       reinterpret_cast<HandleScopeImplementer*>(storage);
   List<void**>* blocks_of_archived_thread = thread_local->Blocks();
   v8::ImplementationUtilities::HandleScopeData* handle_data_of_archived_thread =
       &thread_local->handle_scope_data_;
   Iterate(v, blocks_of_archived_thread, handle_data_of_archived_thread);
 
   return storage + ArchiveSpacePerThread();
 }
 
 } }  // namespace v8::internal