Re: [PATCH v5 1/3] refs: allow callers to supply old OIDs for batch deletion

On Thu, Sep 24, 2026 at 09:45:27AM -0700, Junio C Hamano wrote:

Patrick Steinhardt [off-list ref] writes:

quoted

On Wed, Sep 23, 2026 at 11:04:40PM +0200, Maciej Ciemborowicz wrote:

quoted

refs_delete_refs() performs unconditional deletions, so callers cannot
preserve old values that they have already resolved. Consequently,
reference-transaction hooks see a null old OID.

I wasn't paying attention when I gave my reviews, but the above
puzzles me.

"callers cannot preserve", meaning "after deletion the values cannot
be read anymore"?  Of course, but then callers can read them
beforehand and use the stored value when calling hooks later.

Patrick, do you understand these three lines above?  I don't, and I
am asking you because below what you say mostly seems to make sense.

Yeah, I think it's less of a "cannot" but more of a "we do not". I
mentioned this in a later patch, but I think the proper fix for what the
author is after to have reference transactions always resolve the status
quo and provide old object IDs regardless of whether the user provided
one or not. If so we wouldn't have to change any of the interfaces at
all, and we make sure that the reftx hook always gets invoked with
proper old and new OIDs.

Patrick