--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,13 @@
 2010-03-07  Bruno Haible  <bruno@clisp.org>
 
+	Tests of module 'fcntl-h' in C++ mode.
+	* tests/test-fcntl-h-c++.cc: New file.
+	* modules/fcntl-h-tests (Files): Add it and tests/signature.h.
+	(Depends-on): Add ansi-c++-opt.
+	(Makefile.am): Arrange to compile and run test-fcntl-h-c++.
+	* m4/fcntl_h.m4 (gl_FCNTL_MODULE_INDICATOR): Invoke
+	gl_MODULE_INDICATOR.
+
 	Tests of module 'dirent' in C++ mode.
 	* tests/test-dirent-c++.cc: New file.
 	* modules/dirent-tests (Files): Add it and tests/signature.h.

--- a/m4/fcntl_h.m4
+++ b/m4/fcntl_h.m4
@@ -1,4 +1,4 @@
-# serial 10
+# serial 11
 # Configure fcntl.h.
 dnl Copyright (C) 2006, 2007, 2009, 2010 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
@@ -25,6 +25,8 @@
   dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
   AC_REQUIRE([gl_FCNTL_H_DEFAULTS])
   GNULIB_[]m4_translit([$1],[abcdefghijklmnopqrstuvwxyz./-],[ABCDEFGHIJKLMNOPQRSTUVWXYZ___])=1
+  dnl Define it also as a C macro, for the benefit of the unit tests.
+  gl_MODULE_INDICATOR([$1])
 ])
 
 AC_DEFUN([gl_FCNTL_H_DEFAULTS],

--- a/modules/fcntl-h-tests
+++ b/modules/fcntl-h-tests
@@ -1,10 +1,19 @@
 Files:
 tests/test-fcntl-h.c
+tests/test-fcntl-h-c++.cc
+tests/signature.h
 
 Depends-on:
+ansi-c++-opt
 
 configure.ac:
 
 Makefile.am:
 TESTS += test-fcntl-h
 check_PROGRAMS += test-fcntl-h
+if ANSICXX
+TESTS += test-fcntl-h-c++
+check_PROGRAMS += test-fcntl-h-c++
+test_fcntl_h_c___SOURCES = test-fcntl-h-c++.cc
+test_fcntl_h_c___LDADD = $(LDADD) $(LIBINTL) $(LIB_CLOCK_GETTIME)
+endif

new file mode 100644
--- /dev/null
+++ b/tests/test-fcntl-h-c++.cc
@@ -0,0 +1,43 @@
+/* Test of <fcntl.h> substitute in C++ mode.
+   Copyright (C) 2010 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 of the License, 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, see <http://www.gnu.org/licenses/>.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2010.  */
+
+#define GNULIB_NAMESPACE gnulib
+#include <config.h>
+
+#include <fcntl.h>
+
+#include "signature.h"
+
+
+#if GNULIB_FCNTL
+SIGNATURE_CHECK (GNULIB_NAMESPACE::fcntl, int, (int, int, ...));
+#endif
+
+#if GNULIB_OPEN
+SIGNATURE_CHECK (GNULIB_NAMESPACE::open, int, (const char *, int, ...));
+#endif
+
+#if GNULIB_OPENAT
+SIGNATURE_CHECK (GNULIB_NAMESPACE::openat, int, (int, char const *, int, ...));
+#endif
+
+
+int
+main ()
+{
+}