1 files changed, 117 insertions, 0 deletions
diff --git a/tests/test-fchdir.c b/tests/test-fchdir.c
new file mode 100644
index 00000000..0eba209c
--- /dev/null
+++ b/tests/test-fchdir.c
@@ -0,0 +1,117 @@
+/* Test changing to a directory named by a file descriptor.
+   Copyright (C) 2009-2024 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 Eric Blake <ebb9@byu.net>, 2009.  */
+
+#include <config.h>
+
+#include <unistd.h>
+
+#include "signature.h"
+SIGNATURE_CHECK (fchdir, int, (int));
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "cloexec.h"
+#include "macros.h"
+
+int
+main (void)
+{
+  char *cwd;
+  int fd;
+  int i;
+
+  cwd = getcwd (NULL, 0);
+  ASSERT (cwd);
+
+  fd = open (".", O_RDONLY);
+  ASSERT (0 <= fd);
+
+  /* Test behaviour for invalid file descriptors.  */
+  {
+    errno = 0;
+    ASSERT (fchdir (-1) == -1);
+    ASSERT (errno == EBADF);
+  }
+  {
+    close (99);
+    errno = 0;
+    ASSERT (fchdir (99) == -1);
+    ASSERT (errno == EBADF);
+  }
+#ifdef FD_ATCWD
+  {
+    errno = 0;
+    ASSERT (fchdir (FD_ATCWD) == -1);
+    ASSERT (errno == EBADF);
+  }
+#endif
+
+  /* Check for other failure cases.  */
+  {
+    int bad_fd = open ("/dev/null", O_RDONLY);
+    ASSERT (0 <= bad_fd);
+    errno = 0;
+    ASSERT (fchdir (bad_fd) == -1);
+    ASSERT (errno == ENOTDIR);
+    ASSERT (close (bad_fd) == 0);
+  }
+
+  /* Repeat test twice, once in '.' and once in '..'.  */
+  for (i = 0; i < 2; i++)
+    {
+      ASSERT (chdir (&".."[1 - i]) == 0);
+      ASSERT (fchdir (fd) == 0);
+      {
+        size_t len = strlen (cwd) + 1;
+        char *new_dir = malloc (len);
+        ASSERT (new_dir);
+        ASSERT (getcwd (new_dir, len) == new_dir);
+        ASSERT (strcmp (cwd, new_dir) == 0);
+        free (new_dir);
+      }
+
+      /* For second iteration, use a cloned fd, to ensure that dup
+         remembers whether an fd was associated with a directory.  */
+      if (!i)
+        {
+          int new_fd = dup (fd);
+          ASSERT (0 <= new_fd);
+          ASSERT (close (fd) == 0);
+          ASSERT (dup2 (new_fd, fd) == fd);
+          ASSERT (close (new_fd) == 0);
+          ASSERT (dup_cloexec (fd) == new_fd);
+          ASSERT (dup2 (new_fd, fd) == fd);
+          ASSERT (close (new_fd) == 0);
+          ASSERT (fcntl (fd, F_DUPFD_CLOEXEC, new_fd) == new_fd);
+          ASSERT (close (fd) == 0);
+          ASSERT (fcntl (new_fd, F_DUPFD, fd) == fd);
+          ASSERT (close (new_fd) == 0);
+#if GNULIB_TEST_DUP3
+          ASSERT (dup3 (fd, new_fd, 0) == new_fd);
+          ASSERT (dup3 (new_fd, fd, 0) == fd);
+          ASSERT (close (new_fd) == 0);
+#endif
+        }
+    }
+
+  free (cwd);
+  return test_exit_status;
+}