Version 6.1.0

• BUGFIX: Don't double-encode URLs (Roderick Monje).
• BUGFIX: Only use the content_type when it exists (Jean-Philippe Doyle).
• STABILITY: Better handling of the content-disposition header. Now supports file name that is either enclosed or not in double quotes and is case insensitive as per RC6266 grammar (Hasan Kumar, Yves Riel).
• STABILITY: Change database column type of attachment file size from unsigned 4-byte integer to unsigned 8-byte bigint. The former type limits attachment size to just over 2GB, which can easily be exceeded by a large video file (Laurent Arnoud, Alen Zamanyan).
• STABILITY: Better error message when thumbnail processing errors (Hayden Ball).
• STABILITY: Fix file linking issues around Windows (Akihiko Odaki).
• STABILITY: Files without an extension will now be checked for spoofing attempts (George Walters II).
• STABILITY: Manually close Tempfiles when we are done with them (Erkki Eilonen).

v6.0.0

6.0.0 (2018-03-09):

• Improvement: Depend only on aws-sdk-s3 instead of aws-sdk (#2481)

5.3.0

5.3.0 (2018-03-09):

• Bugfix: Allow paperclip to load in IRB (#2369)
• Bugfix: MIME type detection (#2527)
• Bugfix: Bad tempfile state after symlink failure (#2540)
• Bugfix: Rewind file after Fog bucket creation (#2572)
• Improvement: Use FactoryBot instead of FactoryGirl (#2501)
• Improvement: README updates (#2411, #2433, #2374, #2417, #2536)
• Improvement: Remove Ruby 2.4 deprecation warning (#2401)
• Improvement: Rails 5 migration compatibility (#2470)
• Improvement: Documentation around post processing (#2381)
• Improvement: S3 hostname example documentation (#2379)
• Improvement: Use Terrapin instead of Cocaine (#2553)

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)

v5.1.0

• Add default content_type_detector to UploadedFileAdapter (#2270)
• Default S3 protocol to empty string (#2038)
• Don't write original file if it wasn't reprocessed (#1993)
• Disallow trailing newlines in regular expressions (#2266)
• Support for readbyte in Paperclip attachments (#2034)
• (port from 4.3) Uri io adapter uses the content-disposition filename (#2250)
• General refactors and documentation improvements

v5.0.0

• Bugfix: Now it's possible to save images from URLs with special characters [#1932]
• Bugfix: Return false when file to copy is not present in cloud storage [#2173]
• Automatically close file while checking mime type [#2016]
• Add read_timeout option to UriAdapter#download_content method [#2232]
• Fix a nil error in content type validation matcher [#1910]
• Documentation improvements

v4.3.7

• Add deprecation warnings
• Improvement: Add fog_options configuration to send options to fog when storing files
• Improvement: the URI adapter now uses the content-disposition header to name the downloaded file

v5.0.0.beta2

• Bugfix: Dynamic fog directory option is now respected
• Bugfix: Fixes cocaine duplicated paths [#2169]
• Removal of dead code (older versions of Rails and AWS SDK)
• README adjustments

v5.0.0.beta1

• Drop support to end-of-life'd ruby 2.0.

• Drop support for end-of-life'd Rails 3.2 and 4.1

• Drop support for AWS v1

• Remove tests for JRuby and Rubinius from Travis CI (they were failing)

• Improvement: Add fog_options configuration to send options to fog when
  storing files.

• Extracted repository for locales only: https://github.com/thoughtbot/paperclip-i18n

• Bugfix: Original file could be unlinked during post_process_style, producing failures

• Bugfix for image magick scaling images up

• Memory consumption improvements

• url on a unpersisted record returns default_url rather than nil

• Improvement: aws-sdk v2 support
  #1903

  If your Gemfile contains aws-sdk (>= 2.0.0) and aws-sdk-v1, paperclip will use
  aws-sdk v2. With aws-sdk v2, S3 storage requires you to set the s3_region.
  s3_region may be nested in s3_credentials, and (if not nested in
  s3_credentials) it may be a Proc.

v4.3.6

• Bug Fix: When a spoofed media type is detected, megabytes of mime-types info are added to logs. See https://cwe.mitre.org/data/definitions/779.html.