do_not_validate_attachment_file_type still validating

[persep]

Hi,
I have Ubuntu 14.0.4 64 with rails 4.26 and paperclip 4.3.6.
I have a model called track in track.rb with a do_not_validate_attachment_file_type validation:

class Track < ActiveRecord::Base
    has_many :tracksegments, :dependent => :destroy
    has_many :points, :through => :tracksegments

    has_attached_file :gpx
    validates :name, presence: true
    do_not_validate_attachment_file_type :gpx

    before_save :parse_file
       ...............

According to the docs it shouldn't do any validations but when I load a gps file i get the error
[paperclip] Content Type Spoof: Filename demofile.foo (text/xml from Headers, [] from Extension), content type discovered from file command: application/xml. See documentation to allow this combination.
The only way to bypass the validation is with an initialier in config/initializer/paperclip.rb with:
Paperclip.options[:content_type_mappings] = { :gpx => ["application/xml"] }

Souldn't do_not_validate_attachment_file_type stop all validations?

[persep]

i've just discovered that for do_not_validate_attachment_file_type to stop the validation you have to add an initializer in config/initializer/paperclip.rb
with
Paperclip::Attachment.default_options[:validate_media_type] = false
I couln't find this in the docs only in the NEWS file

[duhaime]

Adding

Paperclip::Attachment.default_options[:validate_media_type] = false

Is not a great idea because it's going to allow all of your attachments to possess any media type (e.g. sketchy.exe will be allowed). It's better to add validate_media_type: false to the has_attached_file block