Sync billing with shipping address on Admin Order Page

 - Added validation for empty applied taxes to avoid exceptions during json decoding

Author: YevSent

app/code/Magento/Quote/Model/Quote/Address.php

@@ -1170,7 +1170,8 @@ public function validateMinimumAmount()
      */
     public function getAppliedTaxes()
     {
-        return $this->serializer->unserialize($this->getData('applied_taxes'));
+        $taxes = $this->getData('applied_taxes');
+        return $taxes ? $this->serializer->unserialize($taxes) : [];
     }
 
     /**

app/code/Magento/Quote/Test/Unit/Model/Quote/AddressTest.php

@@ -9,7 +9,7 @@
 namespace Magento\Quote\Test\Unit\Model\Quote;
 
 use Magento\Directory\Model\Currency;
-use \Magento\Quote\Model\Quote\Address;
+use Magento\Quote\Model\Quote\Address;
 use Magento\Quote\Model\Quote\Address\Rate;
 use Magento\Quote\Model\ResourceModel\Quote\Address\Rate\CollectionFactory as RateCollectionFactory;
 use Magento\Quote\Model\ResourceModel\Quote\Address\Rate\Collection as RatesCollection;
@@ -28,6 +28,7 @@
 use Magento\Store\Api\Data\StoreInterface;
 use Magento\Store\Api\Data\WebsiteInterface;
 use Magento\Quote\Model\Quote\Address\RateResult\AbstractResult;
+use Magento\Framework\Serialize\Serializer\Json;
 
 /**
  * Test class for sales quote address model
@@ -117,7 +118,7 @@ protected function setUp()
         $objectManager = new \Magento\Framework\TestFramework\Unit\Helper\ObjectManager($this);
 
         $this->scopeConfig = $this->createMock(\Magento\Framework\App\Config::class);
-        $this->serializer = $this->createMock(\Magento\Framework\Serialize\Serializer\Json::class);
+        $this->serializer = new Json();
 
         $this->requestFactory = $this->getMockBuilder(RateRequestFactory::class)
             ->disableOriginalConstructor()
@@ -273,20 +274,17 @@ public function testValidateMiniumumAmountNegative()
     public function testSetAndGetAppliedTaxes()
     {
         $data = ['data'];
-        $result = json_encode($data);
-
-        $this->serializer->expects($this->once())
-            ->method('serialize')
-            ->with($data)
-            ->willReturn($result);
-
-        $this->serializer->expects($this->once())
-            ->method('unserialize')
-            ->with($result)
-            ->willReturn($data);
+        self::assertInstanceOf(Address::class, $this->address->setAppliedTaxes($data));
+        self::assertEquals($data, $this->address->getAppliedTaxes());
+    }
 
-        $this->assertInstanceOf(\Magento\Quote\Model\Quote\Address::class, $this->address->setAppliedTaxes($data));
-        $this->assertEquals($data, $this->address->getAppliedTaxes());
+    /**
+     * Checks a case, when applied taxes are not provided.
+     */
+    public function testGetAppliedTaxesWithEmptyValue()
+    {
+        $this->address->setData('applied_taxes', null);
+        self::assertEquals([], $this->address->getAppliedTaxes());
     }
 
     /**

app/code/Magento/Sales/Model/AdminOrder/Create.php

@@ -10,6 +10,7 @@
 
 use Magento\Customer\Api\AddressMetadataInterface;
 use Magento\Customer\Model\Metadata\Form as CustomerForm;
+use Magento\Framework\App\ObjectManager;
 use Magento\Quote\Model\Quote\Address;
 use Magento\Quote\Model\Quote\Item;
 
@@ -324,7 +325,7 @@ public function __construct(
         $this->dataObjectHelper = $dataObjectHelper;
         $this->orderManagement = $orderManagement;
         $this->quoteFactory = $quoteFactory;
-        $this->serializer = $serializer ?: \Magento\Framework\App\ObjectManager::getInstance()
+        $this->serializer = $serializer ?: ObjectManager::getInstance()
             ->get(\Magento\Framework\Serialize\Serializer\Json::class);
         parent::__construct($data);
     }
@@ -1476,8 +1477,8 @@ public function setBillingAddress($address)
         // not assigned billing address should be saved as new
         // but if quote already has the billing address it won't be overridden
         if (empty($billingAddress->getCustomerAddressId())) {
-            $quote->removeAddress($quote->getBillingAddress()->getId());
             $billingAddress->setCustomerAddressId(null);
+            $quote->getBillingAddress()->setCustomerAddressId(null);
         }
         $quote->setBillingAddress($billingAddress);