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Date: Wed, 4 Jan 2017 19:52:46 -0500
From: Rich Felker <dalias@...c.org>
To: musl@...ts.openwall.com
Subject: Re: Edge case: strtol with base==1

On Sun, Jan 01, 2017 at 09:04:48PM -0500, Rich Felker wrote:
> On Sun, Jan 01, 2017 at 04:45:19AM -0600, Ryan Prichard wrote:
> > Hi,
> > 
> > I noticed that musl's strtol function allows a base of 1 by parsing strings
> > of only zeros.  With all other bases less than 0 or greater than 36, strtol
> > fails and sets errno to EINVAL.
> > 
> > Is this an oversight?
> > 
> > Not that it especially *matters*, but my guess is that the behavior isn't
> > POSIX conforming:
> >  - POSIX defines valid "subject sequences" for bases of 0 and 2-36.
> >  - "In other than the C or POSIX locale, additional locale-specific subject
> > sequence forms may be accepted."
> > 
> > In the C locale, musl is accepting a subject sequence of all zeroes, which
> > POSIX doesn't define for a base of 1.
> > 
> > http://pubs.opengroup.org/onlinepubs/9699919799/functions/strtol.html
> 
> Indeed, I think you're right. ISO C does not specify the behavior when
> the base is invalid (it's UB), but POSIX does impose an error
> requirement. It's not clear that it requires other bases to be
> unsupported, just that an error be produced if the base is
> unsupported, but I think the right behavior is not to support a
> nonsense "base 1".

Committing a fix. Thanks.

Rich

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