Link LFS objects when MR is created

This is to avoid errors when pulling LFS objects in context of
the MR's target project.

app/services/lfs_objects_projects/bulk_create_service.rb

@@ -21,8 +21,9 @@ module LfsObjectsProjects
 
     private
 
+    # rubocop: disable CodeReuse/ActiveRecord
     def lfs_objects_projects_map(target_project)
-      project.lfs_objects_projects.map do |objects_project|
+      project.lfs_objects_projects.where.not(lfs_object: target_project.lfs_objects).map do |objects_project|
         {
           lfs_object_id: objects_project.lfs_object_id,
           project_id: target_project.id,
@@ -30,5 +31,6 @@ module LfsObjectsProjects
         }
       end
     end
+    # rubocop: enable CodeReuse/ActiveRecord
   end
 end

app/services/merge_requests/create_service.rb

@@ -27,6 +27,7 @@ module MergeRequests
       create_pipeline_for(issuable, current_user)
       issuable.update_head_pipeline
       Gitlab::UsageDataCounters::MergeRequestCounter.count(:create)
+      link_lfs_objects(issuable)
 
       super
     end
@@ -64,6 +65,14 @@ module MergeRequests
         raise Gitlab::Access::AccessDeniedError
       end
     end
+
+    def link_lfs_objects(issuable)
+      return if issuable.source_project == issuable.target_project
+
+      LfsObjectsProjects::BulkCreateService
+        .new(issuable.source_project, target_project: issuable.target_project)
+        .execute
+    end
   end
 end
 

spec/services/merge_requests/create_service_spec.rb

@@ -483,6 +483,14 @@ describe MergeRequests::CreateService, :clean_gitlab_redis_shared_state do
           expect(merge_request).to be_persisted
         end
 
+        it 'calls LfsObjectsProjects::BulkCreateService#execute', :sidekiq_might_not_need_inline do
+          expect_next_instance_of(LfsObjectsProjects::BulkCreateService) do |service|
+            expect(service).to receive(:execute)
+          end
+
+          described_class.new(project, user, opts).execute
+        end
+
         it 'does not create the merge request when the target project is archived' do
           target_project.update!(archived: true)