fix post version diff method

app/models/post_version.rb

@@ -61,7 +61,7 @@ class PostVersion < ActiveRecord::Base
   end
 
   def sequence_for_post
-    versions = PostVersion.where(:post_id => post_id).order("id desc").all
+    versions = PostVersion.where(:post_id => post_id).order("updated_at desc").all
     diffs = []
     versions.each_index do |i|
       if i < versions.size - 1
@@ -94,7 +94,7 @@ class PostVersion < ActiveRecord::Base
   end
   
   def previous
-    PostVersion.where("post_id = ? and id < ?", post_id, id).order("id desc").first
+    PostVersion.where("post_id = ? and id < ?", post_id, id).order("updated_at desc").first
   end
   
   def truncated_source

app/views/post_versions/_listing.html.erb

@@ -17,7 +17,7 @@
     <tbody>
       <% post_versions.each do |post_version| %>
         <tr id="post-version-<%= post_version.id %>">
-          <td><%= link_to(post_version.post_id, post_path(post_version.post_id)) %></td>
+          <td><%= link_to("#{post_version.post_id}.#{post_version.id}", post_path(post_version.post_id)) %></td>
           <td><%= compact_time(post_version.updated_at) %></td>
           <td>
             <% if post_version.updater %>