CE backport for changes in EE MR 14017

This backports to CE changes to allow the EE model
DesignManagement::Repository to override the #attributes_at method to
provide its own git attributes.

The #attributes_at method was freely available, as it's never called by
anything in the app. It looks like the code that called it got
refactored out of existence in ca66a04f. It was still being called in a
spec
https://gitlab.com/gitlab-org/gitlab-ce/blob/85b29c1c2fa3b94d7371cf454c485457a0756cb1/spec/services/files/create_service_spec.rb#L40
which I've left because with the change in Lfs::FileTransformer in fact
is now again the perfect test!

See EE MR
https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/14017

And these comment threads
https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/13894#note_178002089
https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/13894#note_178049984

app/services/lfs/file_transformer.rb

@@ -4,6 +4,14 @@ module Lfs
   # Usage: Calling `new_file` check to see if a file should be in LFS and
   #        return a transformed result with `content` and `encoding` to commit.
   #
+  #        The `repository` passed to the initializer can be a Repository or
+  #        a DesignManagement::Repository (an EE-specific class that inherits
+  #        from Repository).
+  #
+  #        The `repository_type` property will be one of the types named in
+  #        `Gitlab::GlRepository.types`, and is recorded on the `LfsObjectsProject`
+  #        in order to identify the repository location of the blob.
+  #
   #        For LFS an LfsObject linked to the project is stored and an LFS
   #        pointer returned. If the file isn't in LFS the untransformed content
   #        is returned to save in the commit.
@@ -52,7 +60,7 @@ module Lfs
     end
 
     def cached_attributes
-      @cached_attributes ||= Gitlab::Git::AttributesAtRefParser.new(repository, branch_name)
+      @cached_attributes ||= repository.attributes_at(branch_name)
     end
 
     # rubocop: disable CodeReuse/ActiveRecord

lib/gitlab/git/repository.rb

@@ -683,17 +683,16 @@ module Gitlab
         attributes(path)[name]
       end
 
-      # Check .gitattributes for a given ref
+      # Returns parsed .gitattributes for a given ref
       #
-      # This only checks the root .gitattributes file,
+      # This only parses the root .gitattributes file,
       # it does not traverse subfolders to find additional .gitattributes files
       #
       # This method is around 30 times slower than `attributes`, which uses
       # `$GIT_DIR/info/attributes`. Consider caching AttributesAtRefParser
       # and reusing that for multiple calls instead of this method.
-      def attributes_at(ref, file_path)
-        parser = AttributesAtRefParser.new(self, ref)
-        parser.attributes(file_path)
+      def attributes_at(ref)
+        AttributesAtRefParser.new(self, ref)
       end
 
       def languages(ref = nil)

spec/support/shared_examples/controllers/repository_lfs_file_load_examples.rb

@@ -9,7 +9,15 @@
 # - `filepath`: path of the file (contains filename)
 # - `subject`: the request to be made to the controller. Example:
 # subject { get :show, namespace_id: project.namespace, project_id: project }
-shared_examples 'a controller that can serve LFS files' do
+#
+# The LFS disabled scenario can be skipped by passing `skip_lfs_disabled_tests: true`
+# when including the examples (Note, at time of writing this is only used by
+# an EE-specific spec):
+#
+# it_behaves_like 'a controller that can serve LFS files', skip_lfs_disabled_tests: true do
+#   ...
+# end
+shared_examples 'a controller that can serve LFS files' do |options = {}|
   let(:lfs_oid) { '91eff75a492a3ed0dfcb544d7f31326bc4014c8551849c192fd1e48d4dd2c897' }
   let(:lfs_size) { '1575078' }
   let!(:lfs_object) { create(:lfs_object, oid: lfs_oid, size: lfs_size) }
@@ -83,6 +91,8 @@ shared_examples 'a controller that can serve LFS files' do
     end
 
     it 'delivers ASCII file' do
+      skip 'Calling spec asked to skip testing LFS disabled scenario' if options[:skip_lfs_disabled_tests]
+
       subject
 
       expect(response).to have_gitlab_http_status(200)