test-dup2: enhance test

[gnulib.git] / tests / test-dup2.c

diff --git a/tests/test-dup2.c b/tests/test-dup2.c
index 379a613..e1ffc21 100644 (file)
--- a/tests/test-dup2.c
+++ b/tests/test-dup2.c
@@ -80,6 +80,15 @@ main ()
   ASSERT (dup2 (fd, fd) == fd);
   ASSERT (is_open (fd));
 
+  /* The source must be valid.  */
+  errno = 0;
+  ASSERT (dup2 (-1, fd) == -1);
+  ASSERT (errno == EBADF);
+  errno = 0;
+  ASSERT (dup2 (AT_FDCWD, fd) == -1);
+  ASSERT (errno == EBADF);
+  ASSERT (is_open (fd));
+
   /* If the source is not open, then the destination is unaffected.  */
   errno = 0;
   ASSERT (dup2 (fd + 1, fd + 1) == -1);