def edit_book_comments(comments, book):
    modif_date = False
    if comments:
        comments = clean_html(comments)
    if len(book.comments):
        if book.comments[0].text != comments:
            book.comments[0].text = comments
            modif_date = True
    else:
        if comments:
            book.comments.append(db.Comments(text=comments, book=book.id))
            modif_date = True
    return modif_date
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.