thoughtbot/paperclip — pull request #749 by benmanns (2012-02-21 21:39:50+00:00)
Title: Check file existence in Storage::Fog#to_file.

Storage::Fog#to_file doesn't currently check if the file exists before
trying to download it with Fog. This is contrary to the behavior of
Storage::Filesystem#to_file, and causes errors when assigning in
Attachment#assign.

I believe that there is a similar issue in Storage::S3.