Question about ext2

Hi all!
I look up in implementation in ext2_rename and see the following statment:
       if (S_ISDIR(old_inode->i_mode)) {
                if (new_inode) {
                        retval = -ENOTEMPTY;
                        if (!empty_dir (new_inode))
                                goto end_rename;
                }
But I don't see any checkl like S_ISDIR on new_inode neither in ext2_rename neither in empty_dir. Is this bug? And, anyway, can I rename directory into not-empty file?
Thanks in advance,
	Nikita
P.S. Please, CC answer on [e-mail], because I'm not subscribed on this list