gitlab-org--gitlab-foss/app/policies/ci/pipeline_policy.rb

module Ci
  class PipelinePolicy < BasePolicy
    delegate { @subject.project }

    condition(:protected_ref) { ref_protected?(@user, @subject.project, @subject.tag?, @subject.ref) }

    rule { protected_ref }.prevent :update_pipeline

    def ref_protected?(user, project, tag, ref)
      access = ::Gitlab::UserAccess.new(user, project: project)

      if tag
        !access.can_create_tag?(ref)
      else
        !access.can_update_branch?(ref)
      end
    end
  end
end