blob_set_raw_len(buf->head, blob_pad_len(buf->head) - blob_pad_len(attr));
blob_set_raw_len(attr, blob_raw_len(attr) - maxlen);
blob_set_raw_len(buf->head, blob_pad_len(buf->head) - blob_pad_len(attr));
blob_set_raw_len(attr, blob_raw_len(attr) - maxlen);