fix merge custom file fields

gistfile1.txt

--- C:/Users/Brian/Documents/CLIENT/sites/all/modules/civicrm/CRM/Dedupe/Merger.php	Mon Apr 22 17:11:24 2019
+++ C:/Users/Brian/Documents/CLIENT/sites/all/civicustom/php/CRM/Dedupe/Merger.php	Mon Apr 22 17:36:01 2019
@@ -494,19 +494,18 @@
 
     $mainId = (int) $mainId;
     $otherId = (int) $otherId;
     $multi_value_tables = array_keys(CRM_Dedupe_Merger::getMultiValueCustomSets('cidRefs'));
 
     $sqls = array();
     foreach ($affected as $table) {
+      //LCD skip ALL single-value custom tables
       // skipping non selected single-value custom table's value migration
-      if (!in_array($table, $multi_value_tables)) {
-        if ($customTableToCopyFrom !== NULL && in_array($table, $customTables) && !in_array($table, $customTableToCopyFrom)) {
-          continue;
-        }
+      if (!in_array($table, $multi_value_tables) && in_array($table, $customTables)) {
+        continue;
       }
 
       // Call custom processing function for objects that require it
       if (isset($cpTables[$table])) {
         foreach ($cpTables[$table] as $className => $fnName) {
           $className::$fnName($mainId, $otherId, $sqls, $tables, $tableOperations);
         }
@@ -1718,15 +1717,16 @@
 
       // get the contact_id -> file_id mapping
       $fileIds = array();
       $sql = "SELECT entity_id, {$columnName} AS file_id FROM {$tableName} WHERE entity_id IN ({$mainId}, {$otherId})";
       $dao = CRM_Core_DAO::executeQuery($sql);
       while ($dao->fetch()) {
         $fileIds[$dao->entity_id] = $dao->file_id;
-        if ($dao->entity_id == $mainId) {
+        //LCD only delete reference if file exists
+        if ($dao->entity_id == $mainId && !empty($fileIds[$mainId])) {
           CRM_Core_BAO_File::deleteFileReferences($fileIds[$mainId], $mainId, $customId);
         }
       }
       $dao->free();
 
       // move the other contact's file to main contact
       //NYSS need to INSERT or UPDATE depending on whether main contact has an existing record
@@ -1750,14 +1750,19 @@
       }
       else {
         $sql = "
           INSERT INTO civicrm_entity_file ( entity_table, entity_id, file_id )
           VALUES ( '{$tableName}', {$mainId}, {$fileIds[$otherId]} )";
       }
       CRM_Core_DAO::executeQuery($sql);
+
+      //LCD clear value from Other record
+      $sql = "UPDATE {$tableName} SET {$columnName} = NULL WHERE entity_id = {$otherId}";
+      CRM_Core_DAO::executeQuery($sql);
+
     }
 
     // move view only custom fields CRM-5362
     $viewOnlyCustomFields = array();
     foreach ($submitted as $key => $value) {
       $fid = CRM_Core_BAO_CustomField::getKeyID($key);
       if ($fid && array_key_exists($fid, $cFields) && !empty($cFields[$fid]['attributes']['is_view'])