项目历史记录中“查看差别”：建议只有当issue描述内容更行时才“查看差别”，否则只显示一条更新记录即可

app/helpers/issues_helper.rb

@@ -416,12 +416,14 @@ module IssuesHelper
     if detail.property == 'attr' && detail.prop_key == 'description'
       s = l(:text_journal_changed_no_detail, :label => label)
       unless no_html
+        if detail.try(:prop_key) == "description"
           diff_link = link_to l(:label_diff),
                               {:controller => 'journals', :action => 'diff', :id => detail.journal_id,
                                :detail_id => detail.id, :only_path => options[:only_path]},
                               :title => l(:label_view_diff)
           s << " (#{ diff_link })"
         end
+      end
       s.html_safe
     elsif detail.value.present?
       case detail.property