+#include <string.h>
+#include <sys/stat.h>
+
+#if HAVE_READLINKAT
+
+# undef readlinkat
+
+ssize_t
+rpl_readlinkat (int fd, char const *file, char *buf, size_t len)
+{
+# if READLINK_TRAILING_SLASH_BUG
+ size_t file_len = strlen (file);
+ if (file_len && file[file_len - 1] == '/')
+ {
+ /* Even if FILE without the slash is a symlink to a directory,
+ both lstat() and stat() must resolve the trailing slash to
+ the directory rather than the symlink. We can therefore
+ safely use stat() to distinguish between EINVAL and
+ ENOTDIR/ENOENT, avoiding extra overhead of rpl_lstat(). */
+ struct stat st;
+ if (stat (file, &st) == 0)
+ errno = EINVAL;
+ return -1;
+ }
+# endif /* READLINK_TRAILING_SLASH_BUG */
+ return readlinkat (fd, file, buf, len);
+}
+
+#else