DDC-1194 - Improve error handling for DQL INSTANCE OF

lib/Doctrine/ORM/Query/QueryException.php

@@ -135,4 +135,10 @@ class QueryException extends \Doctrine\ORM\ORMException
             "in the query."
         );
     }
+    
+    public static function instanceOfUnrelatedClass($className, $rootClass)
+    {
+        return new self("Cannot check if a child of '" . $rootClass . "' is instanceof '" . $className . "', " .
+                "inheritance hierachy exists between these two classes.");
+    }
 }

lib/Doctrine/ORM/Query/SqlWalker.php

@@ -1657,6 +1657,10 @@ class SqlWalker implements TreeWalker
             $sql .= $this->_conn->quote($class->discriminatorValue);
         } else {
             $discrMap = array_flip($class->discriminatorMap);
+            if (!isset($discrMap[$entityClassName])) {
+                throw QueryException::instanceOfUnrelatedClass($entityClassName, $class->rootEntityName);
+            }
+            
             $sql .= $this->_conn->quote($discrMap[$entityClassName]);
         }
 

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

@@ -384,6 +384,28 @@ class SelectSqlGenerationTest extends \Doctrine\Tests\OrmTestCase
         );
     }
     
+    /**
+     * @group DDC-1194
+     */
+    public function testSupportsInstanceOfExpressionsInWherePartPrefixedSlash()
+    {
+        $this->assertSqlGeneration(
+            "SELECT u FROM Doctrine\Tests\Models\Company\CompanyPerson u WHERE u INSTANCE OF \Doctrine\Tests\Models\Company\CompanyEmployee",
+            "SELECT c0_.id AS id0, c0_.name AS name1, c0_.discr AS discr2 FROM company_persons c0_ WHERE c0_.discr = 'employee'"
+        );
+    }
+    
+    /**
+     * @group DDC-1194
+     */
+    public function testSupportsInstanceOfExpressionsInWherePartWithUnrelatedClass()
+    {
+        $this->assertInvalidSqlGeneration(
+            "SELECT u FROM Doctrine\Tests\Models\Company\CompanyPerson u WHERE u INSTANCE OF \Doctrine\Tests\Models\CMS\CmsUser",
+            "Doctrine\ORM\Query\QueryException"
+        );
+    }
+
     public function testSupportsInstanceOfExpressionsInWherePartInDeeperLevel()
     {
         $this->assertSqlGeneration(