MAGETWO-59473: Default address checkbox is unchecked on Customer re-save

Author: xmav

app/code/Magento/Customer/Controller/Adminhtml/Index/Save.php

@@ -84,7 +84,7 @@ protected function _extractData(
         $result = $metadataForm->compactData($formData);
 
         // Re-initialize additional attributes
-        $formData = array_replace($formData, $result);
+        $formData = array_replace($result, $formData);
 
         // Unset unused attributes
         $formAttributes = $metadataForm->getAttributes();

dev/tests/integration/testsuite/Magento/Customer/Controller/Adminhtml/IndexTest.php

@@ -313,6 +313,8 @@ public function testSaveActionExistingCustomerAndExistingAddressData()
         $this->assertEquals(2, count($addresses));
         $updatedAddress = $this->addressRepository->getById(1);
         $this->assertEquals('update firstname', $updatedAddress->getFirstname());
+        $this->assertTrue($updatedAddress->isDefaultBilling());
+        $this->assertEquals($updatedAddress->getId(), $customer->getDefaultBilling());
         $newAddress = $this->accountManagement->getDefaultShippingAddress($customerId);
         $this->assertEquals('new firstname', $newAddress->getFirstname());