Fix disappearing ORDER BY when keyset paginating

lib/gitlab/pagination/keyset/iterator.rb

@@ -9,7 +9,7 @@ module Gitlab
           raise(UnsupportedScopeOrder) unless success
 
           @cursor = cursor
-          @order = Gitlab::Pagination::Keyset::Order.extract_keyset_order_object(scope)
+          @order = Gitlab::Pagination::Keyset::Order.extract_keyset_order_object(@scope)
           @use_union_optimization = in_operator_optimization_options ? false : use_union_optimization
           @in_operator_optimization_options = in_operator_optimization_options
         end

lib/gitlab/pagination/keyset/order.rb

@@ -155,7 +155,7 @@ module Gitlab
         def apply_cursor_conditions(scope, values = {}, options = { use_union_optimization: false, in_operator_optimization_options: nil })
           values ||= {}
           transformed_values = values.with_indifferent_access
-          scope = apply_custom_projections(scope.dup)
+          scope = apply_custom_projections(scope)
 
           where_values = build_where_values(transformed_values)
 

spec/requests/api/graphql/packages/package_spec.rb

@@ -96,4 +96,43 @@ RSpec.describe 'package details' do
       expect(graphql_data_at(:b)).to be(nil)
     end
   end
+
+  context 'when loading pipelines ordered by ID DESC' do
+    let(:pipelines) { create_list(:ci_pipeline, 6, project: project) }
+
+    before do
+      composer_package.pipelines = pipelines
+      composer_package.save!
+    end
+
+    def run_query(args)
+      pipelines_nodes = <<~QUERY
+      nodes {
+        id
+      }
+      pageInfo {
+        endCursor
+      }
+      QUERY
+
+      query = graphql_query_for(:package, { id: package_global_id }, query_graphql_field("pipelines", args, pipelines_nodes))
+      post_graphql(query, current_user: user)
+    end
+
+    it 'loads the second page correctly' do
+      run_query({ first: 2 })
+      cursor = graphql_data.dig('package', 'pipelines', 'pageInfo', 'endCursor')
+
+      run_query({ first: 2, after: cursor })
+
+      expected_pipeline_ids = pipelines
+        .sort_by(&:id)
+        .reverse[2..3] # second page
+        .map { |pipeline| pipeline.to_gid.to_s }
+
+      pipeline_ids = graphql_data.dig('package', 'pipelines', 'nodes').pluck('id')
+
+      expect(pipeline_ids).to eq(expected_pipeline_ids)
+    end
+  end
 end