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From: "Laurent Bercot" <ska-dietlibc@skarnet.org>
To: musl@lists.openwall.com
Subject: Re: [PATCH] scanf: handle the L modifier for integers
Date: Thu, 31 May 2018 14:20:19 +0000	[thread overview]
Message-ID: <em0161a10d-2175-4b96-9d2d-d14cd675eef9@elzian> (raw)
In-Reply-To: <20180531064719.6805-1-avagin@virtuozzo.com>

>Without this patch, ret will be 1 and mask will be 0. It is obviously
>incorrect. According to the man page, L should work like ll:
>
>L Indicates that the conversion will be either e, f, or g and the
>   next pointer is a pointer to long double or the conversion will
>   be d, i, o, u, or x and the next pointer is a pointer to long
>   long.

  This is a GNU extension. POSIX states that L is only valid before
a floating-point conversion specifier:

L
     Specifies that a following a, A, e, E, f, F, g, or G conversion 
specifier
     applies to an argument with type pointer to long double.

  from 
http://pubs.opengroup.org/onlinepubs/9699919799/functions/scanf.html

  So, it is valid for musl not to accept %Lx.
  Now, the argument that it's a good idea to align musl's behaviour to
glibc's whenever possible is a sensible one. But it's a decision for
the musl authors to make, and the pros and cons need to be carefully
balanced; musl's current behaviour is not _incorrect_.

--
  Laurent



  reply	other threads:[~2018-05-31 14:20 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-31  6:47 Andrei Vagin
2018-05-31 14:20 ` Laurent Bercot [this message]
2018-05-31 19:00 ` Andrei Vagin
2018-05-31 20:44   ` Natanael Copa
2018-05-31 21:21     ` Andrei Vagin
2018-05-31 23:44     ` Rich Felker
2018-06-01  0:30       ` Szabolcs Nagy
2018-06-01  0:59         ` Rich Felker
2018-06-01  7:36       ` Andrei Vagin

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