MAGETWO-91626: Countries from default website set when edit order address

- Fix issue with empty region_id

Author: viktym

app/code/Magento/Sales/Block/Adminhtml/Order/Address/Form.php

@@ -106,14 +106,6 @@ protected function _getAddress()
      */
     protected function _prepareForm()
     {
-        $address = $this->_getAddress();
-        if ($address !== null) {
-            $storeId = $this->_getAddress()
-                ->getOrder()
-                ->getStoreId();
-            $this->_storeManager->setCurrentStore($storeId);
-        }
-
         parent::_prepareForm();
         $this->_form->setId('edit_form');
         $this->_form->setMethod('post');

app/code/Magento/Sales/Block/Adminhtml/Order/Create/Form/Address.php

@@ -218,6 +218,11 @@ public function getAddressCollectionJson()
      */
     protected function _prepareForm()
     {
+        $storeId = $this->getCreateOrderModel()
+            ->getSession()
+            ->getStoreId();
+        $this->_storeManager->setCurrentStore($storeId);
+
         $fieldset = $this->_form->addFieldset('main', ['no_container' => true]);
 
         $addressForm = $this->_customerFormFactory->create('customer_address', 'adminhtml_customer_address');

app/code/Magento/Sales/Test/Unit/Block/Adminhtml/Order/Address/FormTest.php

@@ -17,6 +17,7 @@
 use Magento\Framework\Registry;
 use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
 use Magento\Sales\Block\Adminhtml\Order\Address\Form;
+use Magento\Sales\Model\AdminOrder\Create;
 use Magento\Sales\Model\Order;
 use Magento\Sales\Model\Order\Address;
 use PHPUnit_Framework_MockObject_MockObject as MockObject;
@@ -57,6 +58,11 @@ class FormTest extends \PHPUnit\Framework\TestCase
      */
     private $sessionQuote;
 
+    /**
+     * @var Create|MockObject
+     */
+    private $orderCreate;
+
     protected function setUp()
     {
         $objectManager = new ObjectManager($this);
@@ -72,14 +78,21 @@ protected function setUp()
             ->setMethods(['getStoreId', 'getStore'])
             ->getMock();
 
+        $this->orderCreate = $this->getMockBuilder(Create::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+        $this->orderCreate->method('getSession')
+            ->willReturn($this->sessionQuote);
+
         $this->addressBlock = $objectManager->getObject(
             Form::class,
             [
                 '_formFactory' => $this->formFactory,
                 '_customerFormFactory' => $this->customerFormFactory,
                 '_coreRegistry' => $this->coreRegistry,
                 'countriesCollection' => $this->countriesCollection,
-                'sessionQuote' => $this->sessionQuote
+                'sessionQuote' => $this->sessionQuote,
+                '_orderCreate' => $this->orderCreate
             ]
         );
     }