Add latest changes from gitlab-org/gitlab@master

2 files changed, 24 insertions, 3 deletions

diff --git a/app/models/work_item.rb b/app/models/work_item.rb
index ec2071b663f..5ae3fb6cf78 100644
--- a/app/models/work_item.rb
+++ b/app/models/work_item.rb
@@ -17,8 +17,9 @@ class WorkItem < Issue
   has_many :child_links, class_name: '::WorkItems::ParentLink', foreign_key: :work_item_parent_id
   has_many :work_item_children, through: :child_links, class_name: 'WorkItem',
                                 foreign_key: :work_item_id, source: :work_item
-  has_many :work_item_children_by_created_at, -> { order(:created_at) }, through: :child_links, class_name: 'WorkItem',
-                                              foreign_key: :work_item_id, source: :work_item
+  has_many :work_item_children_by_relative_position, -> { work_item_children_keyset_order },
+                                                     through: :child_links, class_name: 'WorkItem',
+                                                     foreign_key: :work_item_id, source: :work_item
 
   scope :inc_relations_for_permission_check, -> { includes(:author, project: :project_feature) }
 
@@ -32,6 +33,26 @@ class WorkItem < Issue
     def test_reports_join_column
       'issues.id'
     end
+
+    def work_item_children_keyset_order
+      keyset_order = Gitlab::Pagination::Keyset::Order.build([
+        Gitlab::Pagination::Keyset::ColumnOrderDefinition.new(
+          attribute_name: :relative_position,
+          column_expression: WorkItems::ParentLink.arel_table[:relative_position],
+          order_expression: WorkItems::ParentLink.arel_table[:relative_position].asc.nulls_last,
+          nullable: :nulls_last,
+          distinct: false
+        ),
+        Gitlab::Pagination::Keyset::ColumnOrderDefinition.new(
+          attribute_name: :created_at,
+          order_expression: WorkItem.arel_table[:created_at].asc,
+          nullable: :not_nullable,
+          distinct: false
+        )
+      ])
+
+      includes(:child_links).order(keyset_order)
+    end
   end
 
   def noteable_target_type_name
diff --git a/app/models/work_items/widgets/hierarchy.rb b/app/models/work_items/widgets/hierarchy.rb
index ee10c631bcc..8f54cb32f43 100644
--- a/app/models/work_items/widgets/hierarchy.rb
+++ b/app/models/work_items/widgets/hierarchy.rb
@@ -8,7 +8,7 @@ module WorkItems
       end
 
       def children
-        work_item.work_item_children_by_created_at
+        work_item.work_item_children_by_relative_position
       end
     end
   end