Fix for issue 25147

- Totals Information Management - setting quote shipping method when address method is not null

Author: joe

app/code/Magento/Checkout/Model/TotalsInformationManagement.php

@@ -52,9 +52,11 @@ public function calculate(
             $quote->setBillingAddress($addressInformation->getAddress());
         } else {
             $quote->setShippingAddress($addressInformation->getAddress());
-            $quote->getShippingAddress()->setCollectShippingRates(true)->setShippingMethod(
-                $addressInformation->getShippingCarrierCode() . '_' . $addressInformation->getShippingMethodCode()
-            );
+            if ($addressInformation->getShippingCarrierCode() && $addressInformation->getShippingMethodCode()) {
+                $quote->getShippingAddress()->setCollectShippingRates(true)->setShippingMethod(
+                    $addressInformation->getShippingCarrierCode().'_'.$addressInformation->getShippingMethodCode()
+                );
+            }
         }
         $quote->collectTotals();