Re: Float value 'Infinity' is cast to numeric 1 on Windows

Hello,

Does it make sense to put a check of "isinf(val)" and ereport prior to
the snprintf()?
It is a lightweight check more than set_var_from_str().

Thanks,

2017-09-27 19:41 GMT+09:00 Taiki Kondo <tai-kondo(at)yk(dot)jp(dot)nec(dot)com>:
> Hi all,
>
> I build PostgreSQL 9.6.5 by Visual Studio 2013 on Windows, I found weird behavior on it.
>
> I execute following SQL, occurring ERROR is expected, but I got mysterious value 1.
>
>
> postgres=# select (float8 'inf')::numeric;
> numeric
> ---------
> 1
> (1 row)
>
>
> On Windows, at least Visual Studio, the string of float/double value meaning
> infinity is "1.#INF" not "inf". So, set_var_from_str() called from float8_numeric()
> in utils/adt/numeric.c will return numeric value 1, and no one checks this situation.
>
> This situation is also occurring by cast from float4.
>
> I wrote a patch to add check this situation.
> Please find attached.
>
>
> Sincerely,
>
> --
> Taiki Kondo
> NEC Solution Innovators, Ltd.
>
>
>
>
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--
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KaiGai Kohei <kaigai(at)heterodb(dot)com>