Re: fix mkostemp, add pipe2-safer

[Bruno Haible]

Hi Eric,

> > - In set_cloexec_flag: You added a call to
> >     dup2 (desc, desc)
> >   But on a POSIX compliant system this is a no-op, since
> 
> Not quite.  It is the fastest one-syscall sequence for determining whether
> an fd is open

Oh, I see. That wasn't clear to me.

> Okay, then, a comment describing that dup2 is used as an EBADF filter, and
> not for any side effects on cloexec (since there aren't any side effects),
> would make sense.

Yes. Two more comments won't harm:


2009-12-09  Bruno Haible  <address@hidden>

        * lib/cloexec.c (set_cloexec_flag): Clarify intent of dup2 call.

*** lib/cloexec.c.orig  2009-12-09 11:19:08.000000000 +0100
--- lib/cloexec.c       2009-12-09 10:55:55.000000000 +0100
***************
*** 71,78 ****
        errno = EBADF;
        return -1;
      }
!   return dup2 (desc, desc) == desc ? 0 : -1;
  
  #endif
  }
  
--- 71,82 ----
        errno = EBADF;
        return -1;
      }
!   if (dup2 (desc, desc) < 0)
!     /* errno is EBADF here.  */
!     return -1;
  
+   /* There is nothing we can do on this kind of platform.  Punt.  */
+   return 0;
  #endif
  }