Add failing test for failing to update child-parent relation when the…

… child has been prefetched in QB

tests/Tests/Models/GH7212/GH7212Child.php

@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\Tests\Models\GH7212;
+
+use Doctrine\ORM\Mapping as ORM;
+
+#[ORM\Entity]
+class GH7212Child
+{
+    /** @var int */
+    #[ORM\Column(type: 'integer')]
+    #[ORM\Id]
+    private $id;
+
+    /** @var GH7212Parent|null */
+    #[ORM\ManyToOne(targetEntity: GH7212Parent::class, inversedBy: 'children')]
+    private $parent;
+
+    public function __construct(int $id, GH7212Parent|null $parent = null)
+    {
+        $this->id = $id;
+
+        $this->setParent($parent);
+    }
+
+    public function getId(): int
+    {
+        return $this->id;
+    }
+
+    public function getParent(): GH7212Parent|null
+    {
+        return $this->parent;
+    }
+
+    public function setParent(GH7212Parent|null $parent): void
+    {
+        $this->parent = $parent;
+    }
+}

tests/Tests/Models/GH7212/GH7212Parent.php

@@ -0,0 +1,52 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\Tests\Models\GH7212;
+
+use Doctrine\Common\Collections\ArrayCollection;
+use Doctrine\Common\Collections\Collection;
+use Doctrine\ORM\Mapping as ORM;
+use Doctrine\ORM\Mapping\Column;
+use Doctrine\ORM\Mapping\Id;
+use Doctrine\ORM\Mapping\OneToMany;
+
+#[ORM\Entity]
+class GH7212Parent
+{
+    /** @var int */
+    #[Id]
+    #[Column(type: 'integer')]
+    private $id;
+
+    /** @var Collection<int, GH7212Child> */
+    #[OneToMany(targetEntity: GH7212Child::class, mappedBy: 'parent', indexBy: 'id')]
+    private $children;
+
+    public function __construct(int $id)
+    {
+        $this->id       = $id;
+        $this->children = new ArrayCollection();
+    }
+
+    public function getId(): int
+    {
+        return $this->id;
+    }
+
+    public function addChild(GH7212Child $child): void
+    {
+        $this->children->set($child->getId(), $child);
+    }
+
+    public function removeChild(GH7212Child $child): void
+    {
+        $this->children->remove($child->getId());
+    }
+
+    /** @return Collection<int, GH7212Child> */
+    public function getChildren(): Collection
+    {
+        return $this->children;
+    }
+}

tests/Tests/ORM/Functional/BasicFunctionalTest.php

@@ -19,10 +19,14 @@
 use Doctrine\Tests\Models\CMS\CmsGroup;
 use Doctrine\Tests\Models\CMS\CmsPhonenumber;
 use Doctrine\Tests\Models\CMS\CmsUser;
+use Doctrine\Tests\Models\GH7212\GH7212Child;
+use Doctrine\Tests\Models\GH7212\GH7212Parent;
 use Doctrine\Tests\OrmFunctionalTestCase;
 use InvalidArgumentException;
 use PHPUnit\Framework\Attributes\Group;
 
+use function assert;
+
 class BasicFunctionalTest extends OrmFunctionalTestCase
 {
     protected function setUp(): void
@@ -1082,4 +1086,45 @@ public function testItThrowsWhenReferenceUsesIdAssignedByDatabase(): void
         // post insert IDs will be assigned during flush
         $this->_em->flush();
     }
+
+    public function testIndexedRelationUpdatesWhenSelectedUsingLeftJoin(): void
+    {
+        $this->_schemaTool->createSchema(
+            [
+                $this->_em->getClassMetadata(GH7212Parent::class),
+                $this->_em->getClassMetadata(GH7212Child::class),
+            ],
+        );
+
+        $parent = new GH7212Parent(1);
+        $child  = new GH7212Child(1, $parent);
+
+        $this->_em->persist($parent);
+        $this->_em->persist($child);
+
+        $this->_em->flush();
+        $this->_em->clear();
+
+        $parent = $this->_em->createQueryBuilder()
+            ->select('p, c')
+            ->from(GH7212Parent::class, 'p')
+            // Prefetching Child relation using left join
+            ->leftJoin('p.children', 'c')
+            ->getQuery()
+            ->getSingleResult();
+        assert($parent instanceof GH7212Parent);
+
+        $children = $parent->getChildren();
+        foreach ($children as $child) {
+            $child->setParent(null);
+            $parent->removeChild($child);
+        }
+
+        $this->_em->flush();
+
+        $childrenRows = $this->_em->getConnection()->fetchAllAssociative('SELECT * FROM GH7212Child');
+        $this->assertCount(1, $childrenRows);
+        $this->assertSame(1, $childrenRows[0]['id']);
+        $this->assertNull($childrenRows[0]['parent_id']);
+    }
 }