From 06f4969c149039c74940604b75d5f44e44de7bfc Mon Sep 17 00:00:00 2001
From: systopia <endres@systopia.de>
Date: Thu, 15 Feb 2018 17:46:26 +0100
Subject: [PATCH] fixing CRM-21773

---
 CRM/Dedupe/Merger.php | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/CRM/Dedupe/Merger.php b/CRM/Dedupe/Merger.php
index 12c3903d8c..414e8f5d43 100644
--- a/CRM/Dedupe/Merger.php
+++ b/CRM/Dedupe/Merger.php
@@ -467,12 +467,15 @@ INNER JOIN  civicrm_membership membership2 ON membership1.membership_type_id = m
 
     $mainId = (int) $mainId;
     $otherId = (int) $otherId;
+    $multi_value_tables = array_keys(CRM_Dedupe_Merger::getMultiValueCustomSets('cidRefs'));
 
     $sqls = array();
     foreach ($affected as $table) {
-      // skipping non selected custom table's value migration
-      if ($customTableToCopyFrom !== NULL && in_array($table, $customTables) && !in_array($table, $customTableToCopyFrom)) {
-        continue;
+      // skipping non selected single-value custom table's value migration
+      if (!in_array($table, $multi_value_tables)) {
+        if ($customTableToCopyFrom !== NULL && in_array($table, $customTables) && !in_array($table, $customTableToCopyFrom)) {
+          continue;
+        }
       }
 
       // Call custom processing function for objects that require it
-- 
2.25.1