lardawge/carrierwave_backgrounder — pull request #67 by stantona (2012-09-20 16:42:00+00:00)
Title: To enqueue, also check the existence of remote_#{column}_url

When creating the image from a remote source via remote_#{column}_url, the job fails to enqueue
because #{column}_changed? is always false. This adds an extra check on the remote_#{column}_url
and if it's not empty, than enqueue the job.

I'm not sure whether this is the correct fix for this. I added these for active record and mongoid, but not for data mapper since I couldn't test it.