Try to add a reproducer for #11488

tests/Tests/ORM/Functional/Ticket/GH11488Test.php

@@ -0,0 +1,65 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\Tests\ORM\Functional\Ticket;
+
+use Doctrine\ORM\Mapping\Driver\AttributeDriver;
+use Doctrine\Tests\ORM\Functional\Ticket\GH11488\Somewhere\BaseEntity;
+use Doctrine\Tests\ORM\Functional\Ticket\GH11488\SomewhereElse\Mother;
+use Doctrine\Tests\ORM\Functional\Ticket\GH11488\YetSomewhereElse\Daughter;
+use Doctrine\Tests\OrmFunctionalTestCase;
+
+class GH11488Test extends OrmFunctionalTestCase
+{
+    protected function setUp(): void
+    {
+        parent::setUp();
+        // $this->_em = $this->getEntityManager(mappingDriver: new AttributeDriver([], reportFieldsWhereDeclared: true));
+
+        $this->setUpEntitySchema([
+            BaseEntity::class,
+            Mother::class,
+            Daughter::class,
+        ]);
+    }
+
+    public function testSchema(): void
+    {
+        $cm = $this->_em->getClassMetadata(Daughter::class);
+
+        self::assertSame([0 => 'id'], $cm->getIdentifier());
+        self::assertSame(['id'], $cm->getFieldNames());
+    }
+}
+
+namespace Doctrine\Tests\ORM\Functional\Ticket\GH11488\Somewhere;
+
+use Doctrine\ORM\Mapping as ORM;
+
+#[ORM\MappedSuperclass]
+abstract class BaseEntity
+{
+    #[ORM\Id, ORM\Column]
+    protected ?int $id;
+}
+
+namespace Doctrine\Tests\ORM\Functional\Ticket\GH11488\SomewhereElse;
+
+use Doctrine\ORM\Mapping as ORM;
+use Doctrine\Tests\ORM\Functional\Ticket\GH11488\Somewhere\BaseEntity;
+
+#[ORM\MappedSuperclass]
+abstract class Mother extends BaseEntity
+{
+}
+
+namespace Doctrine\Tests\ORM\Functional\Ticket\GH11488\YetSomewhereElse;
+
+use Doctrine\ORM\Mapping as ORM;
+use Doctrine\Tests\ORM\Functional\Ticket\GH11488\SomewhereElse\Mother;
+
+#[ORM\Entity]
+class Daughter extends Mother
+{
+}