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Date: Thu, 20 Oct 2016 12:17:43 -0400
From: Rich Felker <dalias@...c.org>
To: musl@...ts.openwall.com
Subject: Re: getopt_long_only

On Thu, Oct 20, 2016 at 01:54:00AM -0400, Rich Felker wrote:
> On Thu, Oct 13, 2016 at 02:40:19PM -0400, Rich Felker wrote:
> > On Thu, Oct 13, 2016 at 01:43:28PM -0400, Daniel Sabogal wrote:
> > > On Thu, Oct 13, 2016 at 10:42 AM, Sidney Manning <sidneym@...eaurora.org> wrote:
> > > > I may have found an issue with this API.  When a double hyphen is
> > > > encountered the API is supposed to return a -1 but I'm seeing a '?'.
> > > >
> > > > My reference is from the Solaris docs which say: "The special option "--"
> > > > can be used to delimit the end of the options; when it is encountered, -1 is
> > > > returned and "--" is skipped.  I attached a test case to show the problem.
> > > >
> > > > I made the following change it will cause the code to punt to getopt when
> > > > just  a "--" is found:
> > > > argv[optind][0] == '-'
> > > > argv[optind][1] == '-'
> > > > argv[optind][2] == NULL
> > > >
> > > > diff --git a/src/misc/getopt_long.c b/src/misc/getopt_long.c
> > > > index 480c001..9764f56 100644
> > > > --- a/src/misc/getopt_long.c
> > > > +++ b/src/misc/getopt_long.c
> > > > @@ -53,7 +53,7 @@ static int __getopt_long_core(int argc, char *const *argv,
> > > > con
> > > >  {
> > > >         optarg = 0;
> > > >         if (longopts && argv[optind][0] == '-' &&
> > > > -               ((longonly && argv[optind][1]) ||
> > > > +               ((longonly && argv[optind][1]) &&
> > > >                  (argv[optind][1] == '-' && argv[optind][2])))
> > > >         {
> > > >                 int colon =
> > > > optstring[optstring[0]=='+'||optstring[0]=='-']==':'
> > > 
> > > This will break getopt_long() since the entire condition won't hold
> > > whenever !longonly.
> > > 
> > > I think just changing the longonly case to the following is sufficient.
> > > 
> > > (longonly && argv[optind][1] && argv[optind][1] != '-')
> > 
> > Yes, that looks like the correct fix.
> 
> Has anyone tested and confirmed this?

I tested and it fixes the testcase, seems correct, and is in a code
path where it only affects getopt_long_only, so I think it's safe to
make this change. Committing a patch.

Rich

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