Re: [PATCH 3/3] reftable tests: avoid "int" overflow, use "uint64_t" - Han-Wen Nienhuys

From: Han-Wen Nienhuys <hanwen@google.com>
To: Taylor Blau <me@ttaylorr.com>
Cc: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>,
	git@vger.kernel.org, "Junio C Hamano" <gitster@pobox.com>,
	"Johannes Schindelin" <johannes.schindelin@gmx.de>
Subject: Re: [PATCH 3/3] reftable tests: avoid "int" overflow, use "uint64_t"
Date: Tue, 11 Jan 2022 20:31:47 +0100	[thread overview]
Message-ID: <CAFQ2z_M0Fjjx8tAd_cXqk9K9q43hwienEy=UsLJi2aW8G3sEwA@mail.gmail.com> (raw)
In-Reply-To: <Yd3aZ5Q9Ph0H+Ijn@nand.local>

On Tue, Jan 11, 2022 at 8:28 PM Taylor Blau <me@ttaylorr.com> wrote:
>
> On Tue, Jan 11, 2022 at 05:40:23PM +0100, Ævar Arnfjörð Bjarmason wrote:
> > diff --git a/reftable/merged_test.c b/reftable/merged_test.c
> > index 24461e8a802..b87ff495dfd 100644
> > --- a/reftable/merged_test.c
> > +++ b/reftable/merged_test.c
> > @@ -24,8 +24,8 @@ license that can be found in the LICENSE file or at
> >  static void write_test_table(struct strbuf *buf,
> >                            struct reftable_ref_record refs[], int n)
> >  {
> > -     int min = 0xffffffff;
> > -     int max = 0;
> > +     uint64_t min = 0xffffffff;
> > +     uint64_t max = 0;
>
> Han-Wen: it looks like the loop below the context here is to set the
> min/max of update_index over all of the ref records?

correct.

> But perhaps not so from a width perspective, if sizeof(int) != 8 (though
> I suspect in practice that we are unlikely to have enough possible
> values of update_index for that to matter).

correct.

> In any case, you're only setting the lower half of `min` high. Maybe:
>
>     uint64_t min = ~0ul;

yeah, that works.

-- 
Han-Wen Nienhuys - Google Munich
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