--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2009-08-22  Bruno Haible  <bruno@clisp.org>
 
+	Tests for module 'pipe2'.
+	* modules/pipe2-tests: New file.
+	* tests/test-pipe2.c: New file.
+
 	New module 'pipe2'.
 	* lib/unistd.in.h (pipe2): New declaration.
 	* lib/pipe2.c: New file.

new file mode 100644
--- /dev/null
+++ b/modules/pipe2-tests
@@ -0,0 +1,11 @@
+Files:
+tests/test-pipe2.c
+
+Depends-on:
+stdbool
+
+configure.ac:
+
+Makefile.am:
+TESTS += test-pipe2
+check_PROGRAMS += test-pipe2

new file mode 100644
--- /dev/null
+++ b/tests/test-pipe2.c
@@ -0,0 +1,153 @@
+/* Test of pipe2.
+   Copyright (C) 2009 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+#include <unistd.h>
+
+#include <fcntl.h>
+#include <stdbool.h>
+
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+/* Get declarations of the Win32 API functions.  */
+# define WIN32_LEAN_AND_MEAN
+# include <windows.h>
+#endif
+
+#include "binary-io.h"
+
+#define ASSERT(expr) \
+  do									     \
+    {									     \
+      if (!(expr))							     \
+        {								     \
+          fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \
+          fflush (stderr);						     \
+          abort ();							     \
+        }								     \
+    }									     \
+  while (0)
+
+/* Return true if FD is open.  */
+static bool
+is_open (int fd)
+{
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+  /* On Win32, the initial state of unassigned standard file
+     descriptors is that they are open but point to an
+     INVALID_HANDLE_VALUE, and there is no fcntl.  */
+  return (HANDLE) _get_osfhandle (fd) != INVALID_HANDLE_VALUE;
+#else
+# ifndef F_GETFL
+#  error Please port fcntl to your platform
+# endif
+  return 0 <= fcntl (fd, F_GETFL);
+#endif
+}
+
+/* Return true if FD is not inherited to child processes.  */
+static bool
+is_cloexec (int fd)
+{
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+  HANDLE h = (HANDLE) _get_osfhandle (fd);
+  DWORD flags;
+  ASSERT (GetHandleInformation (h, &flags));
+  return (flags & HANDLE_FLAG_INHERIT) == 0;
+#else
+  int flags;
+  ASSERT ((flags = fcntl (fd, F_GETFD)) >= 0);
+  return (flags & FD_CLOEXEC) != 0;
+#endif
+}
+
+/* Return true if FD is in non-blocking mode.  */
+static bool
+is_nonblocking (int fd)
+{
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+  /* We don't use the non-blocking mode for sockets here.  */
+  return 0;
+#else
+  int flags;
+  ASSERT ((flags = fcntl (fd, F_GETFL)) >= 0);
+  return (flags & O_NONBLOCK) != 0;
+#endif
+}
+
+int
+main ()
+{
+  int use_nonblocking;
+  int use_cloexec;
+
+#if !((defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__)
+  for (use_nonblocking = 0; use_nonblocking <= 1; use_nonblocking++)
+#else
+  use_nonblocking = 0;
+#endif
+#if defined O_CLOEXEC
+    for (use_cloexec = 0; use_cloexec <= 1; use_cloexec++)
+#else
+    use_cloexec = 0;
+#endif
+      {
+	int o_flags;
+	int fd[2];
+
+	o_flags = 0;
+#if !((defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__)
+	if (use_nonblocking)
+	  o_flags |= O_NONBLOCK;
+#endif
+#if defined O_CLOEXEC
+	if (use_cloexec)
+	  o_flags |= O_CLOEXEC;
+#endif
+
+	fd[0] = -1;
+	fd[1] = -1;
+	ASSERT (pipe2 (fd, o_flags) >= 0);
+	ASSERT (fd[0] >= 0);
+	ASSERT (fd[1] >= 0);
+	ASSERT (fd[0] != fd[1]);
+	ASSERT (is_open (fd[0]) >= 0);
+	ASSERT (is_open (fd[1]) >= 0);
+	if (use_cloexec)
+	  {
+	    ASSERT (is_cloexec (fd[0]));
+	    ASSERT (is_cloexec (fd[1]));
+	  }
+	else
+	  {
+	    ASSERT (!is_cloexec (fd[0]));
+	    ASSERT (!is_cloexec (fd[1]));
+	  }
+	if (use_nonblocking)
+	  {
+	    ASSERT (is_nonblocking (fd[0]));
+	    ASSERT (is_nonblocking (fd[1]));
+	  }
+	else
+	  {
+	    ASSERT (!is_nonblocking (fd[0]));
+	    ASSERT (!is_nonblocking (fd[1]));
+	  }
+      }
+
+  return 0;
+}