CMS Page - Force validate layout update xml, even in production mode, when saving CMS Page

app/code/Magento/Cms/Controller/Adminhtml/Page/PostDataProcessor.php

@@ -6,6 +6,9 @@
  */
 namespace Magento\Cms\Controller\Adminhtml\Page;
 
+use Magento\Cms\Model\Page\DomValidationState;
+use Magento\Framework\App\ObjectManager;
+
 class PostDataProcessor
 {
     /**
@@ -23,19 +26,28 @@ class PostDataProcessor
      */
     protected $messageManager;
 
+    /**
+     * @var DomValidationState
+     */
+    private $validationState;
+
     /**
      * @param \Magento\Framework\Stdlib\DateTime\Filter\Date $dateFilter
      * @param \Magento\Framework\Message\ManagerInterface $messageManager
      * @param \Magento\Framework\View\Model\Layout\Update\ValidatorFactory $validatorFactory
+     * @param DomValidationState $validationState
      */
     public function __construct(
         \Magento\Framework\Stdlib\DateTime\Filter\Date $dateFilter,
         \Magento\Framework\Message\ManagerInterface $messageManager,
-        \Magento\Framework\View\Model\Layout\Update\ValidatorFactory $validatorFactory
+        \Magento\Framework\View\Model\Layout\Update\ValidatorFactory $validatorFactory,
+        DomValidationState $validationState = null
     ) {
         $this->dateFilter = $dateFilter;
         $this->messageManager = $messageManager;
         $this->validatorFactory = $validatorFactory;
+        $this->validationState = $validationState
+            ?: ObjectManager::getInstance()->get(DomValidationState::class);
     }
 
     /**
@@ -68,7 +80,11 @@ public function validate($data)
         $errorNo = true;
         if (!empty($data['layout_update_xml']) || !empty($data['custom_layout_update_xml'])) {
             /** @var $validatorCustomLayout \Magento\Framework\View\Model\Layout\Update\Validator */
-            $validatorCustomLayout = $this->validatorFactory->create();
+            $validatorCustomLayout = $this->validatorFactory->create(
+                [
+                    'validationState' => $this->validationState,
+                ]
+            );
             if (!empty($data['layout_update_xml']) && !$validatorCustomLayout->isValid($data['layout_update_xml'])) {
                 $errorNo = false;
             }

app/code/Magento/Cms/Model/Page/DomValidationState.php

@@ -0,0 +1,26 @@
+<?php
+/**
+ * Application config file resolver
+ *
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+namespace Magento\Cms\Model\Page;
+
+/**
+ * Class DomValidationState
+ * @package Magento\Cms\Model\Page
+ */
+class DomValidationState implements \Magento\Framework\Config\ValidationStateInterface
+{
+    /**
+     * Retrieve validation state
+     * Used in cms page post processor to force validate layout update xml
+     *
+     * @return boolean
+     */
+    public function isValidationRequired()
+    {
+        return true;
+    }
+}

lib/internal/Magento/Framework/View/Model/Layout/Update/Validator.php

@@ -5,8 +5,11 @@
  */
 namespace Magento\Framework\View\Model\Layout\Update;
 
+use Magento\Framework\App\ObjectManager;
 use Magento\Framework\Config\Dom\UrnResolver;
 use Magento\Framework\Config\Dom\ValidationSchemaException;
+use Magento\Framework\Config\DomFactory;
+use Magento\Framework\Config\ValidationStateInterface;
 
 /**
  * Validator for custom layout update
@@ -54,17 +57,24 @@ class Validator extends \Zend_Validate_Abstract
     protected $_xsdSchemas;
 
     /**
-     * @var \Magento\Framework\Config\DomFactory
+     * @var DomFactory
      */
     protected $_domConfigFactory;
 
     /**
-     * @param \Magento\Framework\Config\DomFactory $domConfigFactory
+     * @var ValidationStateInterface
+     */
+    private $validationState;
+
+    /**
+     * @param DomFactory $domConfigFactory
      * @param \Magento\Framework\Config\Dom\UrnResolver $urnResolver
+     * @param ValidationStateInterface $validationState
      */
     public function __construct(
-        \Magento\Framework\Config\DomFactory $domConfigFactory,
-        UrnResolver $urnResolver
+        DomFactory $domConfigFactory,
+        UrnResolver $urnResolver,
+        ValidationStateInterface $validationState = null
     ) {
         $this->_domConfigFactory = $domConfigFactory;
         $this->_initMessageTemplates();
@@ -76,6 +86,8 @@ public function __construct(
                 'urn:magento:framework:View/Layout/etc/layout_merged.xsd'
             ),
         ];
+        $this->validationState = $validationState
+            ?: ObjectManager::getInstance()->get(ValidationStateInterface::class);
     }
 
     /**
@@ -122,7 +134,13 @@ public function isValid($value, $schema = self::LAYOUT_SCHEMA_PAGE_HANDLE, $isSe
         try {
             //wrap XML value in the "layout" and "handle" tags to make it validatable
             $value = '<layout xmlns:xsi="' . self::XML_NAMESPACE_XSI . '">' . $value . '</layout>';
-            $this->_domConfigFactory->createDom(['xml' => $value, 'schemaFile' => $this->_xsdSchemas[$schema]]);
+            $this->_domConfigFactory->createDom(
+                [
+                    'xml' => $value,
+                    'schemaFile' => $this->_xsdSchemas[$schema],
+                    'validationState' => $this->validationState,
+                ]
+            );
 
             if ($isSecurityCheck) {
                 $value = new \Magento\Framework\Simplexml\Element($value);

lib/internal/Magento/Framework/View/Test/Unit/Model/Layout/Update/ValidatorTest.php

@@ -30,6 +30,11 @@ class ValidatorTest extends \PHPUnit\Framework\TestCase
      */
     private $urnResolver;
 
+    /**
+     * @var \Magento\Framework\Config\ValidationStateInterface|\PHPUnit_Framework_MockObject_MockObject
+     */
+    private $validationState;
+
     protected function setUp()
     {
         $this->_objectHelper = new \Magento\Framework\TestFramework\Unit\Helper\ObjectManager($this);
@@ -39,10 +44,17 @@ protected function setUp()
         $this->urnResolver = $this->getMockBuilder(
             \Magento\Framework\Config\Dom\UrnResolver::class
         )->disableOriginalConstructor()->getMock();
+        $this->validationState = $this->getMockBuilder(
+            \Magento\Framework\Config\ValidationStateInterface::class
+        )->disableOriginalConstructor()->getMock();
 
         $this->model = $this->_objectHelper->getObject(
             \Magento\Framework\View\Model\Layout\Update\Validator::class,
-            ['domConfigFactory' => $this->domConfigFactory, 'urnResolver' => $this->urnResolver]
+            [
+                'domConfigFactory' => $this->domConfigFactory,
+                'urnResolver' => $this->urnResolver,
+                'validationState' => $this->validationState,
+            ]
         );
     }
 
@@ -56,6 +68,7 @@ protected function _createValidator($layoutUpdate)
             'xml' => '<layout xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">' .
                 trim($layoutUpdate) . '</layout>',
             'schemaFile' => $this->urnResolver->getRealPath('urn:magento:framework:View/Layout/etc/page_layout.xsd'),
+            'validationState' => $this->validationState,
         ];
 
         $this->domConfigFactory->expects(