Hi Collin,
> Currently dup3 is replaced unconditionally. I made this change in a
> NetBSD virtual machine and the test program passes:
>
> $ git diff .
> diff --git a/lib/dup3.c b/lib/dup3.c
> index a810d3be19..7674f042a4 100644
> --- a/lib/dup3.c
> +++ b/lib/dup3.c
> @@ -34,6 +34,15 @@ dup3 (int oldfd, int newfd, int flags)
> /* Avoid a cygwin crasher. */
> setdtablesize (newfd + 1);
> # endif
> +
> +#ifdef __NetBSD__
> + if (newfd == oldfd)
> + {
> + errno = EINVAL;
> + return -1;
> + }
> +#endif
> +
> /* Try the system call first, if it exists. (We may be running with a
> glibc
> that has the function but with an older kernel that lacks it.) */
> {
An interesting approach. But I think this added code comes too early:
In case of oldfd == newfd && newfd < 0, it would fail with EINVAL instead
of EBADF.
How about trying the system call first, and test for newfd == oldfd only if
that system call succeeds?
Bruno
