From: Joakim Sindholt <opensource@zhasha.com>
To: musl@lists.openwall.com
Subject: Re: [musl] ecvt(0, 0, ...) is broken
Date: Tue, 6 Sep 2022 14:13:11 +0200 [thread overview]
Message-ID: <20220906141311.b8650027f3499c080f45b4fd@zhasha.com> (raw)
In-Reply-To: <6c1dfc63-b3e8-46a3-1db1-4d5bdf031086@gmail.com>
On Tue, 6 Sep 2022 12:12:48 +0200, Gabriel Ravier <gabravier@gmail.com> wrote:
> Executing ecvt(0, 0, &decpt, &sign) results in musl returning
> "000000000000000".
>
> This seems highly likely to be a bug considering that glibc returns ""
> and I see no plausible reasoning for musl's behavior that could be
> justified by the standard.
POSIX.1-2001 said:
> The ecvt() function shall convert value to a null-terminated string of
> ndigit digits (where ndigit is reduced to an unspecified limit
> determined by the precision of a double) and return a pointer to the
> string. The high-order digit shall be non-zero, unless the value is 0.
The first part would imply that ndigit=0 should return the string "" but
the second part makes no provision for a zero-digit-long string.
I would say ndigit=0 is UB.
next prev parent reply other threads:[~2022-09-06 12:13 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-06 9:27 [musl] Bug report: fcvt seems dysfunctional Gabriel Ravier
2022-09-06 10:12 ` [musl] ecvt(0, 0, ...) is broken Gabriel Ravier
2022-09-06 12:13 ` Joakim Sindholt [this message]
2022-09-06 12:21 ` Gabriel Ravier
2022-09-06 14:17 ` Rich Felker
2022-09-06 18:48 ` Markus Wichmann
2022-09-06 19:19 ` Rich Felker
2022-09-07 3:39 ` Markus Wichmann
2022-09-07 3:51 ` Jeffrey Walton
2022-09-07 13:44 ` Rich Felker
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