MAGETWO-70797: Use backend model also for default config values #7742

Author: Oleksii Korshenko

app/code/Magento/Config/Block/System/Config/Form.php

@@ -427,21 +427,21 @@ private function getFieldData(\Magento\Config\Model\Config\Structure\Element\Fie
         if ($data === null) {
             if (array_key_exists($path, $this->_configData)) {
                 $data = $this->_configData[$path];
-
-                if ($field->hasBackendModel()) {
-                    $backendModel = $field->getBackendModel();
-                    $backendModel->setPath($path)
-                        ->setValue($data)
-                        ->setWebsite($this->getWebsiteCode())
-                        ->setStore($this->getStoreCode())
-                        ->afterLoad();
-                    $data = $backendModel->getValue();
-                }
             } elseif ($field->getConfigPath() !== null) {
                 $data = $this->getConfigValue($field->getConfigPath());
             } else {
                 $data = $this->getConfigValue($path);
             }
+
+            if ($field->hasBackendModel()) {
+                $backendModel = $field->getBackendModel();
+                $backendModel->setPath($path)
+                    ->setValue($data)
+                    ->setWebsite($this->getWebsiteCode())
+                    ->setStore($this->getStoreCode())
+                    ->afterLoad();
+                $data = $backendModel->getValue();
+            }
         }
 
         return $data;

app/code/Magento/Config/Test/Unit/Block/System/Config/FormTest.php

@@ -676,7 +676,7 @@ public function initFieldsDataProvider()
                 true,
                 'Config Value',
                 null,
-                0,
+                1,
                 true,
                 false,
                 true

dev/tests/integration/testsuite/Magento/PageCache/Model/ConfigTest.php

@@ -63,7 +63,7 @@ protected function setUp()
             'accessList' =>  explode(',', '127.0.0.1,192.168.0.1,127.0.0.2'),
             'designExceptions' => json_decode('{"_":{"regexp":"\/firefox\/i","value":"Magento\/blank"}}', true),
             'sslOffloadedHeader' => 'X-Forwarded-Proto',
-            'gracePeriod' => null
+            'gracePeriod' => 1234
         ];
         $vclGeneratorFactory->expects($this->any())
             ->method('create')
@@ -73,7 +73,7 @@ protected function setUp()
                 'example.com',
                 '8080',
                 explode(',', '127.0.0.1,192.168.0.1,127.0.0.2'),
-                null,
+                1234,
                 'X-Forwarded-Proto',
                 json_decode('{"_":{"regexp":"\/firefox\/i","value":"Magento\/blank"}}', true)
             )));
@@ -89,6 +89,7 @@ protected function setUp()
     /**
      * @magentoConfigFixture default/system/full_page_cache/varnish/backend_host example.com
      * @magentoConfigFixture default/system/full_page_cache/varnish/backend_port 8080
+     * @magentoConfigFixture default/system/full_page_cache/varnish/grace_period 1234
      * @magentoConfigFixture default/system/full_page_cache/varnish/access_list 127.0.0.1,192.168.0.1,127.0.0.2
      * @magentoConfigFixture current_store design/theme/ua_regexp {"_":{"regexp":"\/firefox\/i","value":"Magento\/blank"}}
      * @magentoAppIsolation enabled