DDC-1298 - Fix bug in SQLWalker with derived entities that have no fields of their own.

lib/Doctrine/ORM/Query/SqlWalker.php

@@ -511,7 +511,7 @@ class SqlWalker implements TreeWalker
     public function walkSelectClause($selectClause)
     {
         $sql = 'SELECT ' . (($selectClause->isDistinct) ? 'DISTINCT ' : '') . implode(
-            ', ', array_map(array($this, 'walkSelectExpression'), $selectClause->selectExpressions)
+            ', ', array_filter(array_map(array($this, 'walkSelectExpression'), $selectClause->selectExpressions))
         );
 
         $addMetaColumns = ! $this->_query->getHint(Query::HINT_FORCE_PARTIAL_LOAD) &&

tests/Doctrine/Tests/Models/DDC117/DDC117Article.php

@@ -27,6 +27,11 @@ class DDC117Article
      */
     private $translations;
 
+    /**
+     * @OneToMany(targetEntity="DDC117Link", mappedBy="source")
+     */
+    private $links;
+
     public function __construct($title)
     {
         $this->title = $title;

tests/Doctrine/Tests/ORM/Query/SelectSqlGenerationTest.php

@@ -965,6 +965,17 @@ class SelectSqlGenerationTest extends \Doctrine\Tests\OrmTestCase
             "SELECT c0_.id AS id0, c0_.status AS status1, c0_.username AS username2, c0_.name AS name3, (SELECT c1_.name FROM cms_users c1_ WHERE c1_.id = c0_.id AND c1_.name IN (SELECT c2_.name FROM cms_users c2_)) AS sclr4 FROM cms_users c0_"
         );
     }
+
+    /**
+     * @group DDC-1298
+     */
+    public function testSelectForeignKeyPKWithoutFields()
+    {
+        $this->assertSqlGeneration(
+            "SELECT t, s, l FROM Doctrine\Tests\Models\DDC117\DDC117Link l INNER JOIN l.target t INNER JOIN l.source s",
+            "SELECT d0_.article_id AS article_id0, d0_.title AS title1, d1_.article_id AS article_id2, d1_.title AS title3 FROM DDC117Link d2_ INNER JOIN DDC117Article d0_ ON d2_.target_id = d0_.article_id INNER JOIN DDC117Article d1_ ON d2_.source_id = d1_.article_id"
+        );
+    }
 }
 
 

tests/Doctrine/Tests/OrmFunctionalTestCase.php

@@ -98,6 +98,7 @@ abstract class OrmFunctionalTestCase extends OrmTestCase
             'Doctrine\Tests\Models\DDC117\DDC117ArticleDetails',
             'Doctrine\Tests\Models\DDC117\DDC117ApproveChanges',
             'Doctrine\Tests\Models\DDC117\DDC117Editor',
+            'Doctrine\Tests\Models\DDC117\DDC117Link',
         ),
         'stockexchange' => array(
             'Doctrine\Tests\Models\StockExchange\Bond',
@@ -191,6 +192,7 @@ abstract class OrmFunctionalTestCase extends OrmTestCase
             $conn->executeUpdate('DELETE FROM ddc117editor_ddc117translation');
             $conn->executeUpdate('DELETE FROM DDC117Editor');
             $conn->executeUpdate('DELETE FROM DDC117ApproveChanges');
+            $conn->executeUpdate('DELETE FROM DDC117Link');
             $conn->executeUpdate('DELETE FROM DDC117Reference');
             $conn->executeUpdate('DELETE FROM DDC117ArticleDetails');
             $conn->executeUpdate('DELETE FROM DDC117Translation');