retval = rename(oldname, newname);

	CWD_STATE_FREE(&old_state);
	CWD_STATE_FREE(&new_state);

	/* rename on windows will fail if newname already exists.
	   MoveFileEx has to be used */
#ifdef TSRM_WIN32
	/* MoveFileEx returns 0 on failure, other way 'round for this function */
	retval = (MoveFileEx(oldname, newname, MOVEFILE_REPLACE_EXISTING|MOVEFILE_COPY_ALLOWED) == 0) ? -1 : 0;
#else
	retval = rename(oldname, newname);
#endif

	CWD_STATE_FREE(&old_state);
	CWD_STATE_FREE(&new_state);

	return retval;