5.2.1

5.2.1 (2018-01-25):

• Bugfix: Fix copying files on Windows. (#2532)

5.2.0 (2018-01-23):

• Security: Remove the automatic loading of URI adapters. Some of these
  adapters can be specially crafted to expose your network topology. (#2435)

• Bugfix: The rake task no longer rescues Exception. (#2476)

• Bugfix: Handle malformed Content-Disposition headers (#2283)

• Bugfix: The :only_process option works when passed a lambda again. (#2289)

• Improvement: Added :use_accelerate_endpoint option when using S3 to enable
  Amazon S3 Transfer Acceleration
  (#2291)

• Improvement: Make the fingerprint digest configurable per attachment. The
  default remains MD5. Making this configurable means it can change in a future
  version because it is not considered secure anymore against intentional file
  corruption. For more info, see https://en.wikipedia.org/wiki/MD5#Security

  You can change the digest used for an attachment by adding the
  :adapter_options parameter to the has_attached_file options like this:
  has_attached_file :avatar, adapter_options: { hash_digest: Digest::SHA256 }

  Use the rake task to regenerate fingerprints with the new digest for a given
  class. Note that this does not check the file integrity using the old
  fingerprint. Run the following command to regenerate fingerprints for all
  User attachments:
  CLASS=User rake paperclip:refresh:fingerprints
  You can optionally limit the attachment that will be processed, e.g:
  CLASS=User ATTACHMENT=avatar rake paperclip:refresh:fingerprints (#2229)

• Improvement: The new frame_index option on the thumbnail processor allows
  you to select a specific frame from an animated upload to use as a thumbnail.
  Initial support is for mkv, avi, MP4, mov, MPEG, and GIF. (#2155)

• Improvement: Instead of copying files, use hard links. This is an
  optimization. (#2120)

• Improvement: S3 storage option :s3_prefixes_in_alias. (#2287)

• Improvement: Fog option :fog_public can be a lambda. (#2302)

• Improvement: One fewer warning on JRuby. (#2352)