MAGETWO-56936: [Backport][Github] Allowed countries for customer address in admin using storeview configuration #2946

Author: Sergii Kovalenko

app/code/Magento/Customer/Setup/UpgradeData.php

@@ -181,6 +181,21 @@ private function mergeAllowedCountries(array $countries, array $newCountries, $i
         return $countries;
     }
 
+    /**
+     * Retrieve unqiue allowed countries by scope
+     *
+     * @param string $scope
+     * @param int $scopeCode
+     * @return array
+     */
+    private function getAllowedCountries($scope, $scopeCode)
+    {
+        $allowedCountriesReader = $this->getAllowedCountriesReader();
+        return $allowedCountriesReader->getUniqueCountries(
+            $allowedCountriesReader->getCountriesFromConfig($scope, $scopeCode)
+        );
+    }
+
     /**
      * Migrate and merge allowed countries
      *
@@ -189,21 +204,21 @@ private function mergeAllowedCountries(array $countries, array $newCountries, $i
      */
     private function migrateStoresAllowedCountriesToWebsite(SetupInterface $setup)
     {
-        $allowedCountriesReader = $this->getAllowedCountriesReader();
+
         $allowedCountries = [];
         //Process Websites
         foreach ($this->getStoreManager()->getStores() as $store) {
             $allowedCountries = $this->mergeAllowedCountries(
                 $allowedCountries,
-                $allowedCountriesReader->getAllowedCountries(ScopeInterface::SCOPE_STORE, $store->getId()),
+                $this->getAllowedCountries(ScopeInterface::SCOPE_STORE, $store->getId()),
                 $store->getWebsiteId()
             );
         }
         //Process stores
         foreach ($this->getStoreManager()->getWebsites() as $website) {
             $allowedCountries = $this->mergeAllowedCountries(
                 $allowedCountries,
-                $allowedCountriesReader->getAllowedCountries(ScopeInterface::SCOPE_WEBSITE, $website->getId()),
+                $this->getAllowedCountries(ScopeInterface::SCOPE_WEBSITE, $website->getId()),
                 $website->getId()
             );
         }

app/code/Magento/Directory/Model/AllowedCountries.php

@@ -105,7 +105,7 @@ private function getDefaultScopeCode($scope)
      * @param array $allowedCountries
      * @return array
      */
-    private function getUniqueCountries(array $allowedCountries)
+    public function getUniqueCountries(array $allowedCountries)
     {
         return array_combine($allowedCountries, $allowedCountries);
     }
@@ -117,7 +117,7 @@ private function getUniqueCountries(array $allowedCountries)
      * @param int $scopeCode
      * @return array
      */
-    private function getCountriesFromConfig($scope, $scopeCode)
+    public function getCountriesFromConfig($scope, $scopeCode)
     {
         return explode(
             ',',