Conditional versions created with ':from_version' are always processed

[iBublik]

Assuming we have the following setup

class AvatarUploader < CarrierWave::Uploader::Base
  include CarrierWave::MiniMagick

  storage :file

  version :small, from_version: :cropped, if: :process_small? do
    process resize_to_fit: [150, 150]
  end

  version :cropped do
    process resize_to_fit: [200, 200]
  end

  private

  def process_small?
    !model.skip_processing_small_avatar
  end
end

class User < ActiveRecord::Base
  mount_uploader :avatar, AvatarUploader

  attr_writer :skip_processing_small_avatar
end

When we try to disable processing of version, it doesn't work:

user = User.new
user.skip_processing_small_avatar = true
user.avatar = File.open(my_file)
user.avatar.small.exists? # true

If we define the nested version, everything works as expected:

class AvatarUploader < CarrierWave::Uploader::Base
  # other code is the same

  version :cropped do
    process resize_to_fit: [200, 200]
   
    version :small, if: :process_small? do
      process resize_to_fit: [150, 150]
    end
  end
end

user = User.new
user.skip_processing_small_avatar = true
user.avatar = File.open(my_file)
user.avatar.cropped.small.exists? # false

Related code

Callback:

carrierwave/lib/carrierwave/uploader/versions.rb

Line 17 in 2a0fefc

after :cache, :cache_versions!

carrierwave/lib/carrierwave/uploader/versions.rb

Lines 252 to 254 in 2a0fefc

	def versions_to_cache
	@versions_to_cache || dependent_versions
	end

Sibling versions are always included here, whether they're active or not:

carrierwave/lib/carrierwave/uploader/versions.rb

Lines 290 to 292 in 2a0fefc

	end.to_a + sibling_versions.select do |name, v|
	v.class.version_options[:from_version] == self.class.version_names.last
	end.to_a

I guess sibling versions should be also filtered this way:

sibling_versions.select do |version, _uploader|
  version.class.version_options[:from_version] == self.class.version_names.last && 
    parent_version.version_exists?(version)
end.to_a

I can create PR if you also think that it's a bug and not expected behavior.