Add ci_new_artifact_file_reader FF again

This is a revert commit of b5c271db

config/feature_flags/development/ci_new_artifact_file_reader.yml

+---
+name: ci_new_artifact_file_reader
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/46552
+rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/273755
+milestone: '13.6'
+type: development
+group: group::pipeline authoring
+default_enabled: false

lib/gitlab/ci/artifact_file_reader.rb

@@ -45,6 +45,14 @@ module Gitlab
       end
 
       def read_zip_file!(file_path)
+        if ::Feature.enabled?(:ci_new_artifact_file_reader, job.project, default_enabled: false)
+          read_with_new_artifact_file_reader(file_path)
+        else
+          read_with_legacy_artifact_file_reader(file_path)
+        end
+      end
+
+      def read_with_new_artifact_file_reader(file_path)
         job.artifacts_file.use_open_file do |file|
           zip_file = Zip::File.new(file, false, true)
           entry = zip_file.find_entry(file_path)
@@ -61,6 +69,25 @@ module Gitlab
         end
       end
 
+      def read_with_legacy_artifact_file_reader(file_path)
+        job.artifacts_file.use_file do |archive_path|
+          Zip::File.open(archive_path) do |zip_file|
+            entry = zip_file.find_entry(file_path)
+            unless entry
+              raise Error, "Path `#{file_path}` does not exist inside the `#{job.name}` artifacts archive!"
+            end
+
+            if entry.name_is_directory?
+              raise Error, "Path `#{file_path}` was expected to be a file but it was a directory!"
+            end
+
+            zip_file.get_input_stream(entry) do |is|
+              is.read
+            end
+          end
+        end
+      end
+
       def max_archive_size_in_mb
         ActiveSupport::NumberHelper.number_to_human_size(MAX_ARCHIVE_SIZE)
       end

spec/lib/gitlab/ci/artifact_file_reader_spec.rb

@@ -18,6 +18,17 @@ RSpec.describe Gitlab::Ci::ArtifactFileReader do
         expect(YAML.safe_load(subject).keys).to contain_exactly('rspec', 'time', 'custom')
       end
 
+      context 'when FF ci_new_artifact_file_reader is disabled' do
+        before do
+          stub_feature_flags(ci_new_artifact_file_reader: false)
+        end
+
+        it 'returns the content at the path' do
+          is_expected.to be_present
+          expect(YAML.safe_load(subject).keys).to contain_exactly('rspec', 'time', 'custom')
+        end
+      end
+
       context 'when path does not exist' do
         let(:path) { 'file/does/not/exist.txt' }
         let(:expected_error) do