#1866: Improve karabako matching

app/models/post.rb

@@ -332,7 +332,7 @@ class Post < ActiveRecord::Base
       when %r{\Ahttp://(?:fc|th)\d{2}\.deviantart\.net/.+/[a-z0-9_]+_by_([a-z0-9_]+)-d([a-z0-9]+)\.}i
         "http://#{$1}.deviantart.com/gallery/#/d#{$2}"
 
-      when %r{\Ahttp://www\.karabako\.net/images/karabako_(\d+)\.}i
+      when %r{\Ahttp://www\.karabako\.net/images(?:ub)?/karabako_(\d+)(?:_\d+)?\.}i
         "http://www.karabako.net/post/view/#{$1}"
 
       when %r{\Ahttp://p\.twpl\.jp/show/orig/([a-z0-9]+)}i