MAGETWO-69848: Fix #9924, prefill prefix and suffix in checkout shipping address #9925

Author: Oleksii Korshenko

app/code/Magento/Checkout/Block/Checkout/AttributeMerger.php

@@ -315,26 +315,35 @@ protected function getMultilineFieldConfig($attributeCode, array $attributeConfi
      */
     protected function getDefaultValue($attributeCode)
     {
+        if ($attributeCode === 'country_id') {
+            return $this->directoryHelper->getDefaultCountry();
+        }
+
+        $customer = $this->getCustomer();
+        if ($customer === null) {
+            return null;
+        }
+
+        $attributeValue = null;
         switch ($attributeCode) {
+            case 'prefix':
+                $attributeValue = $customer->getPrefix();
+                break;
             case 'firstname':
-                if ($this->getCustomer()) {
-                    return $this->getCustomer()->getFirstname();
-                }
+                $attributeValue = $customer->getFirstname();
                 break;
             case 'middlename':
-                if ($this->getCustomer()) {
-                    return $this->getCustomer()->getMiddlename();
-                }
+                $attributeValue = $customer->getMiddlename();
                 break;
             case 'lastname':
-                if ($this->getCustomer()) {
-                    return $this->getCustomer()->getLastname();
-                }
+                $attributeValue = $customer->getLastname();
+                break;
+            case 'suffix':
+                $attributeValue = $customer->getSuffix();
                 break;
-            case 'country_id':
-                return $this->directoryHelper->getDefaultCountry();
         }
-        return null;
+
+        return $attributeValue;
     }
 
     /**