fix #2012

app/helpers/note_versions_helper.rb

@@ -0,0 +1,30 @@
+module NoteVersionsHelper
+  def note_version_body_diff_info(note_version)
+    previous = note_version.previous
+    if previous.nil?
+      return ""
+    end
+
+    html = ""
+    if note_version.body == previous.body
+      html += '<span class="inactive">(body not changed)</span>'
+    end
+
+    html.html_safe
+  end
+
+  def note_version_position_diff(note_version)
+    previous = note_version.previous
+
+    html = "#{note_version.width}x#{note_version.height}"
+    html += " #{note_version.x},#{note_version.y}"
+    if previous.nil?
+      html
+    elsif note_version.x == previous.x && note_version.y == previous.y && note_version.width == previous.width && note_version.height == previous.height
+      html
+    else
+      html = '<span style="text-decoration: underline;">' + html + '</span>'
+      html.html_safe
+    end
+  end
+end

app/models/note_version.rb

@@ -28,6 +28,10 @@ class NoteVersion < ActiveRecord::Base
     self.updater_ip_addr = CurrentUser.ip_addr
   end
 
+  def previous
+    NoteVersion.where("note_id = ? and created_at < ?", note_id, created_at).order("created_at desc").first
+  end
+
   def updater_name
     User.id_to_name(updater_id)
   end

app/views/note_versions/index.html.erb

@@ -9,6 +9,7 @@
           <th width="5%">Post</th>
           <th width="5%">Note</th>
           <th>Body</th>
+          <th width="5%">Position</th>
           <% if CurrentUser.is_janitor? %>
             <th width="10%">IP Address</th>
           <% end %>
@@ -30,6 +31,10 @@
               <% unless note_version.is_active? %>
                 <span class="inactive">(deleted)</span>
               <% end %>
+              <%= note_version_body_diff_info(note_version) %>
+            </td>
+            <td>
+              <%= note_version_position_diff(note_version) %>
             </td>
             <% if CurrentUser.is_janitor? %>
               <td>