Issue #3366843: Fix tests broken on PHP 8.3

core/modules/editor/src/EditorXssFilter/Standard.php

@@ -94,7 +94,10 @@ protected static function filterXssDataAttributes($html) {
         // value. There is no need to explicitly decode $node->value, since the
         // DOMAttr::value getter returns the decoded value.
         $value = Xss::filterAdmin($node->value);
-        $node->value = Html::escape($value);
+        // Work around https://github.com/php/php-src/issues/8388
+        // Assigning to $node->value decodes the value, contrary to the DOM spec.
+        $node->value = '';
+        $node->appendChild(new \DOMText($value));
       }
       $html = Html::serialize($dom);
     }