Restore adjustments state after updating

We don't know exactly if all adjustments are closed in all
circumstances, so it's better to be conservative until we figure out.
Chances are that non-completed orders have them open.

app/controllers/spree/orders_controller_decorator.rb

@@ -138,11 +138,19 @@ Spree::OrdersController.class_eval do
     @order.shipment.ensure_correct_adjustment_with_included_tax if @order.shipment
   end
 
-  # Sets the adjustments to open to perform the block's action and closes them back again
+  # Sets the adjustments to open to perform the block's action and restores
+  # their state to whatever the they had.
   def with_open_adjustments
+    previous_states = @order.adjustments.each_with_object({}) do |adjustment, hash|
+      hash[adjustment.id] = adjustment.state
+    end
     @order.adjustments.each(&:open)
+
     yield
-    @order.adjustments.each(&:close)
+
+    @order.adjustments.each_with_index do |adjustment, index|
+      adjustment.update_attribute(:state, previous_states[adjustment.id])
+    end
   end
 
   def discard_empty_line_items

spec/controllers/spree/orders_controller_spec.rb

@@ -164,6 +164,18 @@ describe Spree::OrdersController, type: :controller do
         "1" => {quantity: "99", id: li.id}
       })
     end
+
+    it "keeps the adjustments' previous state" do
+      order = subject.current_order(true)
+      line_item = order.add_variant(create(:simple_product, on_hand: 110).variants.first)
+      adjustment = create(:adjustment, adjustable: order)
+
+      spree_get :update, order: { line_items_attributes: {
+        "1" => { quantity: "99", id: line_item.id }
+      }}
+
+      expect(adjustment.state).to eq('open')
+    end
   end
 
   describe "removing items from a completed order" do
@@ -203,6 +215,17 @@ describe Spree::OrdersController, type: :controller do
         expect(order.adjustment_total).to eq((item_num - 1) * (shipping_fee + payment_fee))
         expect(order.shipment.adjustment.included_tax).to eq 0.6
       end
+
+      it "keeps the adjustments' previous state" do
+        spree_post :update, {
+          order: { line_items_attributes: {
+            "0" => { id: line_item1.id, quantity: 1 },
+            "1" => { id: line_item2.id, quantity: 0 }
+          } }
+        }
+
+        expect(order.adjustments.map(&:state)).to eq(['closed', 'closed', 'closed'])
+      end
     end
 
     context "with enterprise fees" do