+2023-05-05 Bruno Haible <bruno@clisp.org>
+
+ dirfd: Add tests.
+ * tests/test-dirfd.c: New file.
+ * modules/dirfd-tests: New file.
+
2023-05-05 Bruno Haible <bruno@clisp.org>
dirfd: Fix bogus override (regression 2023-04-26).
--- /dev/null
+/* Test of dirfd() function.
+ Copyright (C) 2023 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 <https://www.gnu.org/licenses/>. */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2023. */
+
+#include <config.h>
+
+#include <dirent.h>
+
+#include <stdio.h>
+
+#include "macros.h"
+
+int
+main ()
+{
+#if defined _WIN32 && !defined __CYGWIN__
+ fprintf (stderr, "Skipping test: The DIR type does not contain a file descriptor.\n");
+ return 77;
+#else
+ /* On all other platforms, we expect to have either
+ - a dirfd() function, or
+ - a dirfd macro, or
+ - a DIR struct with a d_fd member, or
+ - a DIR struct with a dd_fd member.
+ If we don't have this, dirfd.c produces a function that always returns -1.
+ Check here that this does not happen. */
+ DIR *d = opendir (".");
+ int fd = dirfd (d);
+ ASSERT (fd >= 0);
+
+ return 0;
+#endif
+}