mysql> DESCRIBE wiki_content_versions;
+-----------------+---------------+------+-----+---------+----------------+
| Field           | Type          | Null | Key | Default | Extra          |
+-----------------+---------------+------+-----+---------+----------------+
| id              | int(11)       | NO   | PRI | NULL    | auto_increment |
| wiki_content_id | int(11)       | NO   | MUL | NULL    |                |
| page_id         | int(11)       | NO   |     | NULL    |                |
| author_id       | int(11)       | YES  |     | NULL    |                |
| data            | longblob      | YES  |     | NULL    |                |
| compression     | varchar(6)    | YES  |     |         |                |
| comments        | varchar(1024) | YES  |     |         |                |
| updated_on      | datetime      | NO   | MUL | NULL    |                |
| version         | int(11)       | NO   |     | NULL    |                |
+-----------------+---------------+------+-----+---------+----------------+
9 rows in set (0.00 sec)

--- app/models/wiki_content.rb.orig 2015-05-17 13:01:37.000000000 -0400
+++ app/models/wiki_content.rb  2015-05-19 13:40:35.285843848 -0400
@@ -21,8 +21,8 @@
   self.locking_column = 'version'
   belongs_to :page, :class_name => 'WikiPage'
   belongs_to :author, :class_name => 'User'
-  validates_presence_of :text
-  validates_length_of :comments, :maximum => 255, :allow_nil => true
+  validates_presence_of :text, :comments
+  validates_length_of :comments, :maximum => 1024, :allow_nil => false
   attr_protected :id

   acts_as_versioned