Fixed label removal from issue

app/models/label.rb

@@ -41,8 +41,8 @@ class Label < ActiveRecord::Base
   scope :templates, -> { where(template: true) }
   scope :with_title, ->(title) { where(title: title) }
   scope :with_lists_and_board, -> { joins(lists: :board).merge(List.movable) }
-  scope :on_group_boards, ->(group_id) { with_lists_and_board.where(boards: { group_id: group_id }) }
   scope :on_project_boards, ->(project_id) { with_lists_and_board.where(boards: { project_id: project_id }) }
+  scope :on_board, ->(board_id) { with_lists_and_board.where(boards: { id: board_id }) }
   scope :order_name_asc, -> { reorder(title: :asc) }
   scope :order_name_desc, -> { reorder(title: :desc) }
   scope :subscribed_by, ->(user_id) { joins(:subscriptions).where(subscriptions: { user_id: user_id, subscribed: true }) }

app/services/boards/issues/move_service.rb

@@ -70,10 +70,8 @@ module Boards
         label_ids =
           if moving_to_list.movable?
             moving_from_list.label_id
-          elsif board.group_board?
-            ::Label.on_group_boards(parent.id).pluck(:label_id)
           else
-            ::Label.on_project_boards(parent.id).pluck(:label_id)
+            ::Label.on_board(board.id).pluck(:label_id)
           end
 
         Array(label_ids).compact

changelogs/unreleased/ccr-51052_keep_labels_on_issue.yml

@@ -0,0 +1,5 @@
+---
+title: Fixed label removal from issue
+merge_request: 22762
+author:
+type: fixed

spec/support/shared_examples/services/boards/issues_move_service.rb

@@ -34,7 +34,7 @@ shared_examples 'issues move service' do |group|
       described_class.new(parent, user, params).execute(issue)
       issue.reload
 
-      expect(issue.labels).to contain_exactly(bug)
+      expect(issue.labels).to contain_exactly(bug, regression)
       expect(issue).to be_closed
     end
   end