lib/45148: dup2(3) and dup3(3) should support EINVAL

[Jukka Ruohonen <jruohonen%iki.fi@localhost>]

>Number:         45148
>Category:       lib
>Synopsis:       dup2(3) and dup3(3) should support EINVAL
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    lib-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Jul 15 08:30:00 +0000 2011
>Originator:     Jukka Ruohonen
>Release:        NetBSD 5.1_STABLE
>Organization:
none
>Environment:
>Description:

In Linux the dup3(3) call fails with EINVAL (a) if the specified flags
contain an invalid value or (b) if "newfd" equals "oldfd". The case (b)
applies also to dup2(3).

>How-To-Repeat:

>Fix:

Make these fail with EINVAL.