MAGETWO-91570: [2.2.x] - [Github]Can not save attribute magento#5907

- test fix

Author: rganin

app/code/Magento/Swatches/Controller/Adminhtml/Product/Attribute/Plugin/Save.php

@@ -24,15 +24,17 @@ class Save
     public function beforeDispatch(Attribute\Save $subject, RequestInterface $request)
     {
         $data = $request->getPostValue();
-        //Data is serialized to overcome issues caused by max_input_vars value if it's modification is unavailable.
-        //See subject controller code and comments for more info.
-        if (isset($data['serialized_swatch_values'])
-            && in_array($data['frontend_input'], ['swatch_visual', 'swatch_text'])
-        ) {
-            $data['serialized_options'] = $data['serialized_swatch_values'];
-        }
-        unset($data['serialized_swatch_values']);
+
         if (isset($data['frontend_input'])) {
+            //Data is serialized to overcome issues caused by max_input_vars value if it's modification is unavailable.
+            //See subject controller code and comments for more info.
+            if (isset($data['serialized_swatch_values'])
+                && in_array($data['frontend_input'], ['swatch_visual', 'swatch_text'])
+            ) {
+                $data['serialized_options'] = $data['serialized_swatch_values'];
+                unset($data['serialized_swatch_values']);
+            }
+
             switch ($data['frontend_input']) {
                 case 'swatch_visual':
                     $data[Swatch::SWATCH_INPUT_TYPE_KEY] = Swatch::SWATCH_INPUT_TYPE_VISUAL;