Remove attachment after transaction commit (#20388).

Patch by Ivan Zabrovskiy.

git-svn-id: http://svn.redmine.org/redmine/trunk@14630 e93f8b46-1217-0410-a6f0-8f06a7374b81

test/unit/attachment_test.rb

@@ -23,6 +23,10 @@ class AttachmentTest < ActiveSupport::TestCase
   fixtures :users, :projects, :roles, :members, :member_roles,
            :enabled_modules, :issues, :trackers, :attachments
 
+  # TODO: remove this with Rails 5 that supports after_commit callbacks
+  # in transactional fixtures (https://github.com/rails/rails/pull/18458)
+  self.use_transactional_fixtures = false
+
   class MockFile
     attr_reader :original_filename, :content_type, :content, :size