MAGETWO-87851: [Forwardport] #13551 Fix json encoded attribute backend type to not encode attribute value multiple times #13640

Author: Stanislav Idolov

app/code/Magento/Catalog/Controller/Adminhtml/Product/Attribute/Save.php

@@ -200,8 +200,6 @@ public function execute()
                 }
             }
 
-            $data = $this->presentation->convertPresentationDataToInputType($data);
-
             if ($attributeId) {
                 if (!$model->getId()) {
                     $this->messageManager->addErrorMessage(__('This attribute no longer exists.'));
@@ -216,6 +214,7 @@ public function execute()
 
                 $data['attribute_code'] = $model->getAttributeCode();
                 $data['is_user_defined'] = $model->getIsUserDefined();
+                $data['frontend_input'] = $model->getFrontendInput();
             } else {
                 /**
                  * @todo add to helper and specify all relations for properties
@@ -228,6 +227,8 @@ public function execute()
                 );
             }
 
+            $data = $this->presentation->convertPresentationDataToInputType($data);
+
             $data += ['is_filterable' => 0, 'is_filterable_in_search' => 0];
 
             if ($model->getIsUserDefined() === null || $model->getIsUserDefined() != 0) {