MAGETWO-84000: Undefined index: region_id is presented after save customer address

Author: Oleksandr Iegorov

app/code/Magento/Customer/Block/Address/Edit.php

@@ -139,8 +139,8 @@ protected function _prepareLayout()
 
         if ($postedData = $this->_customerSession->getAddressFormData(true)) {
             $postedData['region'] = [
-                'region_id' => $postedData['region_id'],
-                'region' => $postedData['region'],
+                'region_id' => $postedData['region_id'] ?? null,
+                'region' => $postedData['region'] ?? null,
             ];
             $this->dataObjectHelper->populateWithArray(
                 $this->_address,

app/code/Magento/Customer/Model/AttributeChecker.php

@@ -8,7 +8,6 @@
 use Magento\Customer\Api\AddressMetadataInterface;
 use Magento\Customer\Api\AddressMetadataManagementInterface;
 use Magento\Customer\Model\Metadata\AttributeResolver;
-use Magento\Framework\App\Helper\Context;
 
 /**
  * Customer attribute checker.