{% block menu %}
<li><a href="{{ book.get_absolute_url }}" id="menu-book" data-box="book-short">
- <img src="{% thumbnail book.cover_thumb '80x111' as thumb %}{{ thumb.url }}{% empty %}{{ book.cover_thumb.url }}{% endthumbnail %}"
+ <img src="{% if book.cover_thumb %}{% thumbnail book.cover_thumb '80x111' as thumb %}{{ thumb.url }}{% empty %}{{ book.cover_thumb.url }}{% endthumbnail %}{% endif %}"
width="80" height="111"
alt="{{ book.pretty_title }}"
title="{{ book.pretty_title }}">