From d6c6e66da1d1c42f23a8eec44e71526826b9d46e Mon Sep 17 00:00:00 2001
From: alojua <juan.alonso@staempfli.com>
Date: Thu, 2 Nov 2017 18:23:17 +0100
Subject: [PATCH 1/2] Fix bug that deletes exiting customer entity Fields, if
 the columns are not present on Import file

---
 .../CustomerImportExport/Model/Import/Customer.php   | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/app/code/Magento/CustomerImportExport/Model/Import/Customer.php b/app/code/Magento/CustomerImportExport/Model/Import/Customer.php
index bee4479526037..1122ac8f17826 100644
--- a/app/code/Magento/CustomerImportExport/Model/Import/Customer.php
+++ b/app/code/Magento/CustomerImportExport/Model/Import/Customer.php
@@ -270,13 +270,23 @@ protected function _saveCustomerEntities(array $entitiesToCreate, array $entitie
             $this->_connection->insertOnDuplicate(
                 $this->_entityTable,
                 $entitiesToUpdate,
-                $this->customerFields
+                $this->getCustomerEntityFieldsToUpdate($entitiesToUpdate)
             );
         }
 
         return $this;
     }
 
+    private function getCustomerEntityFieldsToUpdate(array $entitiesToUpdate): array
+    {
+        $firstCustomer = reset($entitiesToUpdate);
+        $columnsToUpdate = array_keys($firstCustomer);
+        $customerFieldsToUpdate = array_filter($this->customerFields, function ($field) use ($columnsToUpdate) {
+            return in_array($field, $columnsToUpdate);
+        });
+        return $customerFieldsToUpdate;
+    }
+
     /**
      * Save customer attributes.
      *

From 3ae078594c051c551d6b00d6bddc231561465839 Mon Sep 17 00:00:00 2001
From: David Manners <dmanners87@gmail.com>
Date: Thu, 9 Nov 2017 13:37:44 +0000
Subject: [PATCH 2/2] Filter the import to make sure we only update fields
 present in the import file.  - https://github.com/magento/magento2/pull/11968
  - Importing a import file to update customer data, results in entity fields
 being removed if the columns are not present on the imported file.

---
 .../Magento/CustomerImportExport/Model/Import/Customer.php  | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/app/code/Magento/CustomerImportExport/Model/Import/Customer.php b/app/code/Magento/CustomerImportExport/Model/Import/Customer.php
index 1122ac8f17826..016dca2fa526c 100644
--- a/app/code/Magento/CustomerImportExport/Model/Import/Customer.php
+++ b/app/code/Magento/CustomerImportExport/Model/Import/Customer.php
@@ -277,6 +277,12 @@ protected function _saveCustomerEntities(array $entitiesToCreate, array $entitie
         return $this;
     }
 
+    /**
+     * Filter the entity that are being updated so we only change fields found in the importer file
+     *
+     * @param array $entitiesToUpdate
+     * @return array
+     */
     private function getCustomerEntityFieldsToUpdate(array $entitiesToUpdate): array
     {
         $firstCustomer = reset($entitiesToUpdate);