code: func fixWordCntError(wordsInt, wordsFrac int) (newWordsInt int, newWordsFrac int, err error) {
  	if wordsInt+wordsFrac > wordBufLen {
  		if wordsInt > wordBufLen {
  			return wordBufLen, 0, ErrOverflow
  		}
  		return wordsInt, wordBufLen - wordsInt, ErrTruncated
  	}
  	return wordsInt, wordsFrac, nil
  }
docs: // fixWordCntError limits word count in wordBufLen, and returns overflow or truncate error.