To be honest, would make sense to check how this changed between 1.6. and 1.7. But dtype was always NULL, that is why there was no incref (there was no need to define dtype in the first place like that). In the next line I put FORCECAST, I am somewhat guessing it makes no difference at all, but if it does, I am not sure if it is closer to 1.6. or not. I don't think it matters honestly (it would only matter for non array, array likes if at all), but I have no time to investigate anyway right now.