code cleanup: rubocop: fix Lint/IneffectiveAccessModifier in app/models/attachment.rb

git-svn-id: http://svn.redmine.org/redmine/trunk@18781 e93f8b46-1217-0410-a6f0-8f06a7374b81

.rubocop_todo.yml

@@ -390,7 +390,6 @@ Lint/HandleExceptions:
 
 Lint/IneffectiveAccessModifier:
   Exclude:
-    - 'app/models/attachment.rb'
     - 'app/models/mail_handler.rb'
 
 Lint/InterpolationCheck:

app/models/attachment.rb

@@ -492,9 +492,11 @@ class Attachment < ActiveRecord::Base
     time.strftime("%Y/%m")
   end
 
+  # Singleton class method is public
+  class << self
     # Returns an ASCII or hashed filename that do not
     # exists yet in the given subdirectory
-  def self.disk_filename(filename, directory=nil)
+    def disk_filename(filename, directory=nil)
       timestamp = DateTime.now.strftime("%y%m%d%H%M%S")
       ascii = ''
       if %r{^[a-zA-Z0-9_\.\-]*$}.match?(filename) && filename.length <= 50
@@ -510,3 +512,4 @@ class Attachment < ActiveRecord::Base
       "#{timestamp}_#{ascii}"
     end
   end
+end