From d088354f46e39fa02de68fb0edc3ccbf143001a1 Mon Sep 17 00:00:00 2001
From: Sam Minnee <sam@silverstripe.com>
Date: Fri, 2 Aug 2019 16:17:42 +1200
Subject: [PATCH] FIX: Write relations when saving in grid-field item edit form

Fixes https://github.com/silverstripe/silverstripe-framework/issues/9162
---
 src/Forms/GridField/GridFieldDetailForm_ItemRequest.php | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/Forms/GridField/GridFieldDetailForm_ItemRequest.php b/src/Forms/GridField/GridFieldDetailForm_ItemRequest.php
index 4b58032e4..02a86869d 100644
--- a/src/Forms/GridField/GridFieldDetailForm_ItemRequest.php
+++ b/src/Forms/GridField/GridFieldDetailForm_ItemRequest.php
@@ -610,9 +610,10 @@ class GridFieldDetailForm_ItemRequest extends RequestHandler
             $this->record = $this->record->newClassInstance($newClassName);
         }
 
-        // Save form and any extra saved data into this dataobject
+        // Save form and any extra saved data into this dataobject.
+        // Set writeComponents = true to write has-one relations / join records
         $form->saveInto($this->record);
-        $this->record->write();
+        $this->record->write(false, false, false, true);
         $this->extend('onAfterSave', $this->record);
 
         $extraData = $this->getExtraSavedData($this->record, $list);