MAGETWO-35748: Default Values are Set Every Time for Some Config Settings

- fixed

Author: Ivan Gavryshko

lib/internal/Magento/Framework/Config/ConfigGenerator.php

@@ -170,7 +170,12 @@ public function createDbConfig(array $data)
             }
         }
 
-        $configData->set(ConfigOptionsList::CONFIG_PATH_DB_CONNECTION_DEFAULT . ConfigOptionsList::KEY_ACTIVE, '1');
+        if ($this->deploymentConfig->get(
+                ConfigOptionsList::CONFIG_PATH_DB_CONNECTION_DEFAULT . ConfigOptionsList::KEY_ACTIVE
+            ) === null
+        ) {
+            $configData->set(ConfigOptionsList::CONFIG_PATH_DB_CONNECTION_DEFAULT . ConfigOptionsList::KEY_ACTIVE, '1');
+        }
 
         return $configData;
     }
@@ -184,7 +189,9 @@ public function createResourceConfig()
     {
         $configData = new ConfigData(ConfigFilePool::APP_CONFIG);
 
-        $configData->set(ConfigOptionsList::CONFIG_PATH_RESOURCE_DEFAULT_SETUP, 'default');
+        if (!$this->deploymentConfig->get(ConfigOptionsList::CONFIG_PATH_RESOURCE_DEFAULT_SETUP)) {
+            $configData->set(ConfigOptionsList::CONFIG_PATH_RESOURCE_DEFAULT_SETUP, 'default');
+        }
 
         return $configData;
     }

lib/internal/Magento/Framework/Config/ConfigOptionsList.php

@@ -165,7 +165,8 @@ public function getOptions()
                 self::INPUT_KEY_DB_PREFIX,
                 TextConfigOption::FRONTEND_WIZARD_TEXT,
                 self::CONFIG_PATH_DB_PREFIX,
-                'Database table prefix'
+                'Database table prefix',
+                ''
             ),
             new TextConfigOption(
                 self::INPUT_KEY_DB_MODEL,