fix duplicate link without field

application/Espo/Core/Record/Duplicator/EntityDuplicator.php

@@ -31,11 +31,12 @@ namespace Espo\Core\Record\Duplicator;
 
 use Espo\Core\ORM\Type\FieldType;
 use Espo\Core\Utils\Metadata;
+use Espo\ORM\Defs\RelationDefs;
 use Espo\ORM\Entity;
 use Espo\ORM\Defs;
 use Espo\ORM\Defs\FieldDefs;
 use Espo\Core\Utils\FieldUtil;
-
+use Espo\ORM\Type\RelationType;
 use stdClass;
 
 /**
@@ -63,6 +64,10 @@ class EntityDuplicator
             $this->processField($entity, $fieldDefs, $valueMap);
         }
 
+        foreach ($entityDefs->getRelationList() as $relationDefs) {
+            $this->processLink($entity, $relationDefs, $entityDefs, $valueMap);
+        }
+
         return $valueMap;
     }
 
@@ -94,6 +99,37 @@ class EntityDuplicator
         }
     }
 
+    private function processLink(
+        Entity $entity,
+        RelationDefs $relationDefs,
+        Defs\EntityDefs $entityDefs,
+        stdClass $valueMap,
+    ): void {
+
+        $link = $relationDefs->getName();
+
+        if (
+            !in_array($relationDefs->getType(), [
+                RelationType::BELONGS_TO,
+                RelationType::BELONGS_TO_PARENT,
+                RelationType::HAS_ONE,
+            ])
+        ) {
+            return;
+        }
+
+        if ($entityDefs->hasField($link)) {
+            return;
+        }
+
+        unset($valueMap->{$link . 'Id'});
+        unset($valueMap->{$link . 'Name'});
+
+        if ($relationDefs->getType() === RelationType::BELONGS_TO_PARENT) {
+            unset($valueMap->{$link . 'Type'});
+        }
+    }
+
     private function toIgnoreField(string $entityType, FieldDefs $fieldDefs): bool
     {
         $type = $fieldDefs->getType();

tests/integration/Espo/Record/EntityDuplicatorTest.php

@@ -0,0 +1,88 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2026 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace tests\integration\Espo\Record;
+
+use Espo\Core\Record\CreateParams;
+use Espo\Core\Record\Duplicator\EntityDuplicator;
+use Espo\Core\Record\ServiceContainer;
+use Espo\Entities\Email;
+use Espo\Entities\User;
+use Espo\Modules\Crm\Entities\Account;
+use Espo\Modules\Crm\Entities\Task;
+use tests\integration\Core\BaseTestCase;
+
+class EntityDuplicatorTest extends BaseTestCase
+{
+    /**
+     * @noinspection PhpUnhandledExceptionInspection
+     */
+    public function testDuplicate(): void
+    {
+        $user = $this->createUser([
+            'userName' => 'test',
+            'type' => User::TYPE_ADMIN,
+        ]);
+
+        $this->auth('test');
+        $this->reCreateApplication();
+
+        $em = $this->getEntityManager();
+
+        $account = $em->getRDBRepositoryByClass(Account::class)->getNew();
+        $account->setName('Account');
+        $em->saveEntity($account);
+
+        $email = $em->getRDBRepositoryByClass(Email::class)->getNew();
+        $email->setSubject('Test');
+        $email->setParent($account);
+        $em->saveEntity($email);
+
+        $taskService = $this->getContainer()
+            ->getByClass(ServiceContainer::class)
+            ->getByClass(Task::class);
+
+        $task = $taskService->create((object) [
+            'name' => 'Task',
+            'originalEmailId' => $email->getId(),
+            'parentId' => $account->getId(),
+            'parentType' => $account->getEntityType(),
+            'assignedUserId' => $user->getId(),
+        ], CreateParams::create());
+
+        $this->assertEquals($email->getId(), $task->get('emailId'));
+
+        $duplicator = $this->getInjectableFactory()->create(EntityDuplicator::class);
+
+        $values = $duplicator->duplicate($task);
+
+        $this->assertEquals($account->getId(), $values->accountId ?? null);
+        $this->assertFalse(isset($values->emailId));
+    }
+}