redmine_glossary/app/views/glossary_terms/index.html.erb

<h2><%=l :label_glossary_terms %></h2>

<div class="contextual">
  <%= link_to_if_authorized l(:label_glossary_term_new),
  { controller: :glossary_terms, action: :new, project_id: @project },
  class: 'icon icon-add' %>
</div>

<%= render partial: 'sidebar' %>

<% categorized_terms = @glossary_terms.reject { |t| t.category_id.nil? } %>
<% uncategorized_terms = @glossary_terms.where(category_id: nil) %>

<% categorized_terms.group_by(&:category).each do |category, terms| %>
  <h3><%= category.name %></h3>
  <%= render partial: 'index_in_category', locals: {terms: terms} %>
<% end %>

<h3><%=l :label_not_categorized %></h3>
<%= render 'index_in_category',  terms: uncategorized_terms %>