add orders without billing address to SearchOrders#fetch_orders' results

app/services/search_orders.rb

@@ -19,7 +19,17 @@ class SearchOrders
       includes(:payments, :subscription, :shipments, :bill_address, :distributor, :order_cycle).
       ransack(params[:q])
 
-    @search.result(distinct: true).joins(:bill_address)
+    @search = @search.result(distinct: true)
+
+    if ['bill_address',
+        'billing_address'].any?{ |param|
+         params.dig(:q, :s)&.starts_with?(param)
+       }
+      @search = @search.left_joins(:bill_address).
+        select('spree_addresses.*, spree_orders.*')
+    end
+
+    @search
   end
 
   def search_query

app/views/spree/admin/orders/_table_row.html.haml

@@ -33,7 +33,7 @@
     %a{ href: "mailto:#{order.email}", target: "_blank" }
       = order.email
   %td
-    = order.bill_address.full_name_for_sorting
+    = order&.bill_address.full_name_for_sorting
   %td.align-center
     %span
       = order.display_total

spec/controllers/api/v0/orders_controller_spec.rb

@@ -149,6 +149,33 @@ module Api
             .map{ |o| o[:id] }).to eq serialized_orders([order2, order3, order1, order4])
               .map{ |o| o["id"] }
         end
+
+        context "with an order without billing address" do
+          let!(:order7) {
+            create(:order_with_line_items, billing_address: nil, order_cycle: order_cycle,
+                                           distributor: distributor)
+          }
+
+          it 'can show orders without bill address' do
+            get :index, params: { q: {} },
+                        as: :json
+
+            expect(json_response['orders']
+              .map{ |o| o[:id] }).to match_array serialized_orders([order2, order3, order1, order4,
+                                                                    order7])
+                .map{ |o|
+                                                   o["id"]
+                                                 }
+          end
+
+          it 'can sort orders by bill_address.lastname' do
+            get :index, params: { q: { s: 'bill_address_lastname ASC' } },
+                        as: :json
+            expect(json_response['orders']
+              .map{ |o| o[:id] }).to eq serialized_orders([order2, order3, order1, order4, order7])
+                .map{ |o| o["id"] }
+          end
+        end
       end
 
       context 'with pagination' do