jnicklas/carrierwave-mongoid — pull request #58 by Exoth (2012-09-13 11:34:38+00:00)
Title: Identity map + carrierwave-mongoid problem

When the identity map is enabled, ``find_previous_model_for_#{column}`` takes the already modified object from the identity map, so we need to use for_ids, as it ignores the identity map. Another way would be to temporarily disable the identity map.