From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 07 Oct 2026 18:00:56 GMT
Subject: Re: [PATCH 2/2] packfile: fix corruption due to stale delta base cache entries
Message-ID: <xmqqcxtl8k6f.fsf@gitster.g>
In-Reply-To: <20261007081844.GA606386@coredump.intra.peff.net>

Jeff King <peff@peff.net> writes:

> Ah, I get it now. It is a little funny to key the hash on the in-core
> pointer we happen to have, but it does provide a certain uniqueness. I
> suspect that doing this would be mostly correct:
> ...
> and would trigger the use-after-free, but:
>
>   1. It introduces weird semantic questions, like: what if you freed and
>      then reopened a pack of the same name and it didn't have the same
>      contents?
>
>   2. It's more expensive.
>
>   3. Changing the bug from "hard to detect hash equality mismatch" to
>      "undefined behavior" is not really much of an improvement. ;)
>
> So I think just fixing the bug is good, along with accepting that it
> only triggered in certain specific cases and testing that. And your
> patch looks like the obviously correct fix.

Thanks for writing and reviewing, all.  Very much appreciated.

Let me mark the topic for 'next'.