Description of problem:

A second problem we noticed from the gnulib test is that this
assertion fails with the latest upstream kernel:

      /* Assigning to self is invalid.  */
      errno = 0;
      ASSERT (dup3 (fd, fd, o_flags) == -1);   <--- fails
      ASSERT (errno == EINVAL);

dup3 is not currently specified by POSIX, so technically it is fine
for dup3 on Linux to do anything it likes.

*However* the proposal for dup3 in POSIX:

  http://austingroupbugs.net/view.php?id=411

says:

  "The dup3( ) function shall be equivalent to the dup2( ) function if
  the flag argument is 0, except that it shall be an error if fildes
  is equal to fildes2."

So it's probably a good idea for Linux not to regress here.

(Thanks Jim Meyering for finding the link)

Version-Release number of selected component (if applicable):

3.7.0-0.rc0.git2.4.fc19.x86_64

How reproducible:

100%