Hi Bruno,
On 5/17/24 2:10 PM, Bruno Haible wrote:
> On NetBSD 9.0 and 10.0, I always see the same tests fail:
>
> FAIL: test-dup3
> ===============
>
> ../../gltests/test-dup3.c:113: assertion 'dup3 (fd, fd, o_flags) == -1' failed
> FAIL test-dup3 (exit status: 134)
It looks like dup3 behaves differently on NetBSD. It is documented
correctly, but I am not sure the reasoning behind the change.
For NetBSD the return value [1]:
These calls return the new file descriptor value. In the case of dup2()
and dup3() this is always the same as newfd. If an error occurs, the
value -1 is returned and errno is set to indicate what happened.
For GNU/Linux [2]:
If oldfd equals newfd, then dup3() fails with the error
EINVAL.
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.) */
{
Sort of messy but does the trick. I haven't applied it in case you
have any better ideas.
Collin
[1] https://man.netbsd.org/dup3.2
[2] https://man7.org/linux/man-pages/man2/dup3.2.html
