[Python-Dev] Const-correctness in C-API Object Protocol

["Martin v. Löwis"]

> Also changing it now would be a giant hassle, leading to so-called
> "const poisoning" where many, many APIs need to be changed before
> everything would again work.

We have been adding const to many places over the years. I think the
specific case was just missed (i.e. nobody cared about adding const
there).

Regards,
Martin