carrierwaveuploader/carrierwave-mongoid — pull request #122 by Goltergaul (2014-02-20 17:20:40+00:00)
Title: mongoid 4.0.0 renamed metadata method to __metadata

mongoid 4.0.0. broke find_previous_model_for_#{column} method. This is a simple fix

Please let me know if this is a bad idea