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Date:   Mon, 16 Jan 2023 14:51:10 -0500
From:   Jeff King <peff@peff.net>
To:     Junio C Hamano <gitster@pobox.com>
Cc:     git@vger.kernel.org
Subject: Re: [PATCH] format-patch: unleak "-v <num>"
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On Mon, Jan 16, 2023 at 10:35:53AM -0800, Junio C Hamano wrote:

> > The word "unleak" in the subject made me think about UNLEAK(), so this
> > is a small tangent. This is exactly the kind of case that I designed
> > UNLEAK() for, because the solution really is "while you are assigning to
> > X, also keep a copy of the pointer in Y to be freed later".
> 
> Yup.  I was originally planning to use UNLEAK(), but it felt ugly to
> UNLEAK(rev.subject_prefix), as it stores borrowed pointer sometimes
> and owned pointer some other times, which is the exact reason why I
> started looking for a clean way to plug this leak.  So I ended up
> with declaring that the member should only store a borrowed pointer.

That's actually one of the nice things about UNLEAK(). It is OK to
over-mark something that may or may not be allocated.

> The first sentence needs to be rephrased, as it does not make much
> sense to have something usually be X and always be X at the same
> time (I'd just remove "always" from there).

Yep, agreed.

-Peff