Merge pull request #1376 from gmarik/patch-1

removes duplication

lib/paperclip/content_type_detector.rb

@@ -47,14 +47,12 @@ module Paperclip
       File.exists?(@filename) && File.size(@filename) == 0
     end
     
+    alias :empty? :empty_file?
+
     def blank_name?
       @filename.nil? || @filename.empty?
     end
 
-    def empty?
-      File.exists?(@filename) && File.size(@filename) == 0
-    end
-
     def possible_types
       MIME::Types.type_for(@filename).collect(&:content_type)
     end