Re: INTERVAL overflow detection is terribly broken

On Mon, Jan 27, 2014 at 10:48:16PM -0500, Bruce Momjian wrote:
> On Mon, Jan 27, 2014 at 07:19:21PM -0500, Tom Lane wrote:
> > Bruce Momjian <bruce(at)momjian(dot)us> writes:
> > > Oh, one odd thing about this patch. I found I needed to use INT64_MAX,
> > > but I don't see it used anywhere else in our codebase. Is this OK? Is
> > > there a better way?
> >
> > Most of the overflow tests in int.c and int8.c are coded to avoid relying
> > on the MIN or MAX constants; which seemed like better style at the time.
>
> Yes, I looked at those but they seemed like overkill for interval. For
> a case where there was an int64 multiplied by a double, then cast back
> to an int64, I checked the double against INT64_MAX before casting to an
> int64.
>
> > I'm not sure whether relying on INT64_MAX to exist is portable.
>
> The only use I found was in pgbench:
>
> #ifndef INT64_MAX
> #define INT64_MAX INT64CONST(0x7FFFFFFFFFFFFFFF)
> #endif
>
> so I have just added that to my patch, and INT64_MIN:
>
> #ifndef INT64_MIN
> #define INT64_MIN (-INT64CONST(0x7FFFFFFFFFFFFFFF) - 1)
> #endif
>
> This is only used for HAVE_INT64_TIMESTAMP.

Adjusted patch applied for PG 9.4. Thanks for the report.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

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