Re: Potential ABI breakage in upcoming minor releases

On Fri, Nov 15, 2024 at 1:00 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Noah Misch <noah(at)leadboat(dot)com> writes:
> > It's not immediately to clear to me why this would crash in a non-asserts
> > build. palloc issues a 512-byte chunk for sizeof(ResultRelInfo)==368 on
> v16,
> > so I expect no actual writing past the end of the chunk.
>
> I'm confused too. The allocation should be big enough. The other
> hazard would be failing to initialize the field, but if the extension
> uses InitResultRelInfo then that's taken care of.
>

I should have mentioned in my original post that our limited PGD tests are
passing too. But I wasn't sure if the problem may hit us in the field,
given the subtleness of the memory corruption. But it's quite comforting to
read Noah's analysis about why this could be a non-issue for non-assert
builds.

Thanks,
Pavan