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Date: Tue, 12 May 2020 18:13:24 +0300
From: Cyrill Gorcunov <gorcunov@gmail.com>
Message-ID: <20200512151324.GA2219@grain>
References: <cover.1589240704.git.v.shpilevoy@tarantool.org>
 <449685df941ca9a14e102738da413e737e559aea.1589240704.git.v.shpilevoy@tarantool.org>
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In-Reply-To: <449685df941ca9a14e102738da413e737e559aea.1589240704.git.v.shpilevoy@tarantool.org>
Subject: Re: [Tarantool-patches] [PATCH 2/5] decimal: provide MP_DECIMAL
	extension serializer
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To: Vladislav Shpilevoy <v.shpilevoy@tarantool.org>
Cc: tarantool-patches@dev.tarantool.org

On Tue, May 12, 2020 at 01:45:49AM +0200, Vladislav Shpilevoy wrote:
> +
> +int
> +mp_snprint_decimal(char *buf, int size, const char **data, uint32_t len)
> +{
> +	decimal_t d;
> +	if (decimal_unpack(data, len, &d) == NULL)
> +		return -1;
> +	return snprintf(buf, size, "%s", decimal_to_string(&d));
> +}

This looks suspicious -- if buffer size is not enough the snprintf
returns not the number of bytes really written but rather a number
of bytes needed to write the desired string. Are you sure it is
safe to return snprintf result here?