From 3e066db75e495f96d264bf1347b9fec01a44032e Mon Sep 17 00:00:00 2001
From: Pieter Hoste <hoste.pieter@gmail.com>
Date: Tue, 25 Sep 2018 19:57:09 +0200
Subject: [PATCH] Backport 2.2 - Don't set a source model on the attribute when
 it's not needed. This avoids accidentally persisting the source model to the
 database when using multiselect attributes.

(cherry picked from commit 477ca51d052464e862301d945c8bb3550b6fa829)
---
 .../Eav/Model/Entity/Attribute/AbstractAttribute.php        | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/app/code/Magento/Eav/Model/Entity/Attribute/AbstractAttribute.php b/app/code/Magento/Eav/Model/Entity/Attribute/AbstractAttribute.php
index 0f3a1f2220644..65b60be0d96fd 100644
--- a/app/code/Magento/Eav/Model/Entity/Attribute/AbstractAttribute.php
+++ b/app/code/Magento/Eav/Model/Entity/Attribute/AbstractAttribute.php
@@ -594,9 +594,11 @@ public function getSource()
     {
         if (empty($this->_source)) {
             if (!$this->getSourceModel()) {
-                $this->setSourceModel($this->_getDefaultSourceModel());
+                $this->_source = $this->_getDefaultSourceModel();
+            } else {
+                $this->_source = $this->getSourceModel();
             }
-            $source = $this->_universalFactory->create($this->getSourceModel());
+            $source = $this->_universalFactory->create($this->_source);
             if (!$source) {
                 throw new LocalizedException(
                     __(