[PATCH] dup2() should return proper error code

[Andy Shevchenko <andy.shevchenko%gmail.com@localhost>]

When new file descriptor passed to dup2() is out of range the dup2() system
call doesn't return proper error.  Actually the SUSv3 requires correct error
handling:
"If fildes2 is less than 0 or greater than or equal to {OPEN_MAX}, dup2() shall
return -1 with errno set to [EBADF]."

Manual page is leaved the same due to appropriate description of the dup2()
behaviour.
---
 sys/kern/sys_descrip.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/sys/kern/sys_descrip.c b/sys/kern/sys_descrip.c
index 976e653..9a083ea 100644
--- a/sys/kern/sys_descrip.c
+++ b/sys/kern/sys_descrip.c
@@ -127,7 +127,7 @@ sys_dup2(struct lwp *l, const struct sys_dup2_args *uap, 
register_t *retval)
                syscallarg(int) from;
                syscallarg(int) to;
        } */
-       int old, new, error;
+       int old, new, error = 0;
        file_t *fp;
 
        old = SCARG(uap, from);
@@ -147,7 +147,7 @@ sys_dup2(struct lwp *l, const struct sys_dup2_args *uap, 
register_t *retval)
        fd_putfile(old);
        *retval = new;
 
-       return 0;
+       return error;
 }
 
 /*
-- 
1.5.2.5