From 85f36cd1b6c9163bc8e620207bc540b27fb6d3be Mon Sep 17 00:00:00 2001
From: tkotosz <tkotosz@inviqa.com>
Date: Wed, 7 Feb 2018 16:58:00 +0100
Subject: [PATCH 1/2] add failing test for json-encoded attribute backend

---
 .../Attribute/Backend/JsonEncodedTest.php     | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/app/code/Magento/Eav/Test/Unit/Model/Entity/Attribute/Backend/JsonEncodedTest.php b/app/code/Magento/Eav/Test/Unit/Model/Entity/Attribute/Backend/JsonEncodedTest.php
index d94d25e7fd180..3388cbd3052a8 100644
--- a/app/code/Magento/Eav/Test/Unit/Model/Entity/Attribute/Backend/JsonEncodedTest.php
+++ b/app/code/Magento/Eav/Test/Unit/Model/Entity/Attribute/Backend/JsonEncodedTest.php
@@ -82,6 +82,25 @@ public function testBeforeSave()
         $this->assertEquals(json_encode([1, 2, 3]), $product->getData('json_encoded'));
     }
 
+    /**
+     * Test before save handler with already encoded attribute value
+     */
+    public function testBeforeSaveWithAlreadyEncodedValue()
+    {
+        $product = new \Magento\Framework\DataObject(
+            [
+                'json_encoded' => [1, 2, 3]
+            ]
+        );
+
+        // save twice
+        $this->model->beforeSave($product);
+        $this->model->beforeSave($product);
+        
+        // check it is encoded only once
+        $this->assertEquals(json_encode([1, 2, 3]), $product->getData('json_encoded'));
+    }
+
     /**
      * Test after load handler
      */

From 3d10764bbfd0d091e4dd3fb33f165655809f360a Mon Sep 17 00:00:00 2001
From: tkotosz <tkotosz@inviqa.com>
Date: Wed, 7 Feb 2018 17:03:40 +0100
Subject: [PATCH 2/2] fix issue when json encoded attribute backend serialize
 the value multiple times

---
 .../Magento/Eav/Model/Entity/Attribute/Backend/JsonEncoded.php  | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/code/Magento/Eav/Model/Entity/Attribute/Backend/JsonEncoded.php b/app/code/Magento/Eav/Model/Entity/Attribute/Backend/JsonEncoded.php
index 5ea8e97e7004f..31e26cf125abd 100644
--- a/app/code/Magento/Eav/Model/Entity/Attribute/Backend/JsonEncoded.php
+++ b/app/code/Magento/Eav/Model/Entity/Attribute/Backend/JsonEncoded.php
@@ -41,7 +41,7 @@ public function beforeSave($object)
     {
         // parent::beforeSave() is not called intentionally
         $attrCode = $this->getAttribute()->getAttributeCode();
-        if ($object->hasData($attrCode)) {
+        if ($object->hasData($attrCode) && !is_string($object->getData($attrCode))) {
             $object->setData($attrCode, $this->jsonSerializer->serialize($object->getData($attrCode)));
         }
         return $this;