Fix deleting of return_authorizations

return_authorizations have a stock_location_id, not the other way round. So there's no dependent field to nullify.

app/models/spree/return_authorization.rb

@@ -9,7 +9,7 @@ module Spree
     belongs_to :order, class_name: 'Spree::Order', inverse_of: :return_authorizations
 
     has_many :inventory_units, inverse_of: :return_authorization, dependent: :nullify
-    has_one :stock_location, dependent: :nullify
+    has_one :stock_location, dependent: nil
     before_save :force_positive_amount
     before_create :generate_number
 

spec/controllers/spree/admin/return_authorizations_controller_spec.rb

@@ -33,6 +33,18 @@ module Spree
         expect(return_authorization.amount.to_s).to eq "10.2"
         expect(return_authorization.reason.to_s).to eq "half broken"
       end
+
+      context "with a return authorization" do
+        let!(:return_authorization) { create(:return_authorization, order:) }
+
+        it "deletes a return authorization" do
+          expect{
+            spree_delete :destroy, id: return_authorization.id, order_id: order.number
+          }.to change { order.return_authorizations.without_deleted.count }.by(-1)
+
+          expect(response).to redirect_to spree.admin_order_return_authorizations_url(order.number)
+        end
+      end
     end
   end
 end