From: Jeremie Courreges-Anglas <jca@wxcvbn.org>
To: Bruno Haible <bruno@clisp.org>
Cc: bug-gnulib@gnu.org
Subject: Re: vasnprintf: avoid using %n in the general case
Date: Sun, 04 Oct 2020 23:27:45 +0200 [thread overview]
Message-ID: <87imbpadgu.fsf@shannon.wxcvbn.org> (raw)
In-Reply-To: 2804955.gIxoHZPy4Z@omega
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On Sun, Oct 04 2020, Bruno Haible <bruno@clisp.org> wrote:
> Hi Jeremie,
>
>> The attached patch changes vasnprintf.c to avoid using %n in the general
>> case, ie when the return value of snprintf is usable. This should help
>> if more systems decide to make tighten %n usage. There are plans for
>> that in OpenBSD land.
>
> Thanks for the suggestion. Yes, this is a good idea. (I didn't know about
> the OpenBSD plans.)
>
>> The existing comments in vasnprintf.c mention systems where
>> gl_SNPRINTF_RETVAL_C99 and gl_SNPRINTF_TRUNCATION_C99 pass. This patch
>> only considers the usability of the return value of snprintf, as lack
>> of truncation seems to be a different problem (apparently handled later
>> in the code).
>
> I prefer to limit the shortcut to those platforms where both
> gl_SNPRINTF_RETVAL_C99 and gl_SNPRINTF_TRUNCATION_C99 pass. These are
> the conditions I found when considering this code in detail a couple of
> years ago. Maybe you are right that only one of the conditions is needed;
> but I don't want to live on the risky edge here.
Your approach certainly makes sense. I considered something similar
earlier. Your changes look good to me, thanks!
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prev parent reply other threads:[~2020-10-04 21:28 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-03 22:18 vasnprintf: avoid using %n in the general case Jeremie Courreges-Anglas
2020-10-04 15:48 ` Bruno Haible
2020-10-04 21:27 ` Jeremie Courreges-Anglas [this message]
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