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

[Taylor Blau <me@ttaylorr.com>]

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?

If so, making these comparisons all unsigned makes sense to me. In
practice it's probably fine at least from a signedness perspective,
since the compiler _should_ be coercing both operands to unsigned.

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).

In any case, you're only setting the lower half of `min` high. Maybe:

    uint64_t min = ~0ul;

instead?

Thanks,
Taylor