DDC-2780 - Fixed issue with IS NULL on join aliases

lib/Doctrine/ORM/Query/Parser.php

@@ -3264,6 +3264,12 @@ public function NullComparisonExpression()
                     $this->semanticalError('Cannot add having condition on undefined result variable.');
                 }
 
+                // Validate SingleValuedPathExpression (ie.: "product")
+                if (isset($this->queryComponents[$lookaheadValue]['metadata'])) {
+                    $expr = $this->SingleValuedPathExpression();
+                    break;
+                }
+
                 // Validating ResultVariable
                 if ( ! isset($this->queryComponents[$lookaheadValue]['resultVariable'])) {
                     $this->semanticalError('Cannot add having condition on a non result variable.');

tests/Doctrine/Tests/ORM/Functional/Ticket/DDC2780Test.php

@@ -0,0 +1,89 @@
+<?php
+
+namespace Doctrine\Tests\ORM\Functional\Ticket;
+
+use Doctrine\Common\Collections\ArrayCollection;
+
+/**
+ * @group DDC-2780
+ */
+class DDC2780Test extends \Doctrine\Tests\OrmFunctionalTestCase
+{
+    /**
+     * {@inheritDoc}
+     */
+    protected function setup()
+    {
+        parent::setup();
+
+        $this->_schemaTool->createSchema(
+            [
+                $this->_em->getClassMetadata(DDC2780User::class),
+                $this->_em->getClassMetadata(DDC2780Project::class)
+            ]
+        );
+    }
+
+    /**
+     * Verifies that IS [NOT] NULL can be used on join aliases
+     */
+    public function testIssue()
+    {
+        $user    = new DDC2780User;
+        $project = new DDC2780Project;
+
+        $user->project = $project;
+
+        $this->_em->persist($project);
+        $this->_em->persist($user);
+        $this->_em->flush();
+        $this->_em->clear();
+
+        $result = $this->_em->createQueryBuilder()
+            ->select('user')
+            ->from(DDC2780User::class, 'user')
+            ->leftJoin('user.project', 'project')
+            ->where('project IS NOT NULL')
+            ->getQuery()
+            ->getOneOrNullResult();
+
+        $this->assertInstanceOf(DDC2780User::class, $result);
+    }
+}
+
+/**
+ * @Entity
+ */
+class DDC2780User
+{
+    /** @Id @Column(type="integer") @GeneratedValue */
+    public $id;
+
+    /**
+     * @ManyToOne(targetEntity="DDC2780Project")
+     *
+     * @var DDC2780Project
+     */
+    public $project;
+}
+
+/** @Entity */
+class DDC2780Project
+{
+    /** @Id @Column(type="integer") @GeneratedValue */
+    public $id;
+
+    /**
+     * @OneToMany(targetEntity="DDC2780User", mappedBy="project")
+     *
+     * @var DDC2780User[]
+     */
+    public $users;
+
+    /** Constructor */
+    public function __construct()
+    {
+        $this->users = new ArrayCollection();
+    }
+}
+