Re: BUG #17798: Incorrect memory access occurs when using BEFORE ROW UPDATE trigger

On Wed, Jan 10, 2024 at 10:00 PM Alexander Lakhin <exclusion(at)gmail(dot)com> wrote:
> here trigger.c:3055 points at the second call in ExecBRUpdateTriggers():
> newtuple = ExecFetchSlotHeapTuple(newslot, true, &should_free_new);
>
> Does it makes more sense?

Ah, OK, makes tons of sense.

> I was discouraged by that vast distance and implicit buffer usage too, but
> I found no other feasible way to fix it. On the other hand, 75e03eabe and
> Andres's words upthread made me believe that it's an acceptable solution.

I agree that it's potentially acceptable. I just wonder if Tom or
someone else is going to want to propose a bigger change to avoid some
of this messiness. I don't know what that would look like, though.

If not, then I think your patch should be committed and back-patched
pretty much as you have it, except with better comments.

> Thank you very much for diving deep into this subject!

yw.

--
Robert Haas
EDB: http://www.enterprisedb.com