Re: Avoid lost result of recursion (src/backend/optimizer/util/inherit.c)

On Wed, 21 Dec 2022 at 13:15, Ranier Vilela <ranier.vf@gmail.com> wrote:
> IMO, I think that commit a61b1f7, has an oversight.
> Currently is losing the result of recursion of function translate_col_privs_multilevel.
>
> Once the variable result (Bitmapset pointer) is reassigned.
>
> Without a test case for this patch.
> But also, do not have a test case for the current thinko in head.

hmm, that code looks a bit suspect to me too.

Are you able to write a test that shows the bug which fails before
your change and passes after applying it? I don't think it's quite
enough to claim that your changes pass make check given that didn't
fail before your change.

Also, I think it might be better to take the opportunity to rewrite
the function to not use recursion. I don't quite see the need for it
here and it looks like that might have helped contribute to the
reported issue.  Can't we just write this as a while loop instead of
having the function call itself? It's not as if we need stack space
for keeping track of multiple parents. A child relation can only have
1 parent. It seems to me that we can just walk there by looping.

David