+ uid = st.st_uid;
+ }
+# endif
+
+# if CHOWN_MODIFIES_SYMLINK
+ {
+ /* Handle the case in which the system-supplied chown function
+ does *not* follow symlinks. Instead, it changes permissions
+ on the symlink itself. To work around that, we open the
+ file (but this can fail due to lack of read or write permission) and
+ use fchown on the resulting descriptor. */
+ int open_flags = O_NONBLOCK | O_NOCTTY;
+ int fd = open (file, O_RDONLY | open_flags);
+ if (0 <= fd
+ || (errno == EACCES
+ && 0 <= (fd = open (file, O_WRONLY | open_flags))))
+ {
+ int saved_errno;
+ bool fchown_socket_failure;
+
+ result = fchown (fd, uid, gid);
+ saved_errno = errno;
+
+ /* POSIX says fchown can fail with errno == EINVAL on sockets
+ and pipes, so fall back on chown in that case. */
+ fchown_socket_failure =
+ (result != 0 && saved_errno == EINVAL
+ && fstat (fd, &st) == 0
+ && (S_ISFIFO (st.st_mode) || S_ISSOCK (st.st_mode)));
+
+ close (fd);
+
+ if (! fchown_socket_failure)
+ {
+ errno = saved_errno;
+ return result;
+ }
+ }
+ else if (errno != EACCES)
+ return -1;
+ }
+# endif
+
+# if CHOWN_TRAILING_SLASH_BUG
+ if (!stat_valid)
+ {
+ size_t len = strlen (file);
+ if (len && file[len - 1] == '/' && stat (file, &st))
+ return -1;