fix error

app/controllers/galleries_controller.rb

@@ -49,7 +49,7 @@ class GalleriesController < ApplicationController
       thumb_src = a.cover_path(@image_version)
       if thumb_src
         thumb_srcs = thumb_src.split('/')
-        thumb_srcs[-1] = thumb_srcs[-1].sub(/^\w+_/,"")
+        thumb_srcs[-1] = thumb_srcs[-1].sub(/^(?:(?!_).)*_/,"")
         thumb_path = thumb_srcs[0..-2].join('/')
         thumb_path_name = thumb_srcs[-1]
         src = "#{thumb_path}/#{thumb_path_name}"

app/models/album_image.rb

@@ -37,6 +37,14 @@ class AlbumImage
       Album.where(:id=>self.album_id).update_all(:min_order=>min_order + 1)
     end
   end
+  before_save do
+    if self.file_changed?
+      cover = self.album['cover']
+      if cover && cover == self.id
+        self.album.update_attributes({:cover_path => self.file.thumb.url, :cover=> self.id})
+      end
+    end
+  end
   def title_translations
     tmp = super || {}
     if tmp == {}