Added deep clone to QueryBuilder

lib/Doctrine/DBAL/Query/QueryBuilder.php

@@ -1096,4 +1096,36 @@ class QueryBuilder
 
         return $sql;
     }
+
+    /**
+     * Deep clone of all expression objects in the SQL parts.
+     *
+     * @return void
+     */
+    public function __clone()
+    {
+        foreach ($this->sqlParts as $part => $elements) {
+            if (is_array($this->sqlParts[$part])) {
+                foreach ($this->sqlParts[$part] as $idx => $element) {
+                    if (is_object($element)) {
+                        $this->sqlParts[$part][$idx] = clone $element;
+                    }
+                }
+            } else if (is_object($elements)) {
+                $this->sqlParts[$part] = clone $elements;
+            }
+        }
+
+        $params = array();
+
+        foreach ($this->params as $param) {
+            if(is_object($param)){
+                $params[] = clone $param;
+            } else {
+                $params[] = $param;
+            }
+        }
+
+        $this->params = $params;
+    }
 }

tests/Doctrine/Tests/DBAL/Query/QueryBuilderTest.php

@@ -602,4 +602,24 @@ class QueryBuilderTest extends \Doctrine\Tests\DbalTestCase
 
         $this->assertEquals('SELECT DISTINCT u.id FROM users u INNER JOIN permissions p ON p.user_id = u.id, articles a INNER JOIN comments c ON c.article_id = a.id WHERE (u.id = a.user_id) AND (p.read = 1)', $qb->getSQL());
     }
+
+    public function testClone()
+    {
+        $qb = new QueryBuilder($this->conn);
+
+        $qb->select('u.id')
+            ->from('users', 'u')
+            ->where('u.id = :test');
+
+        $qb->setParameter(':test', (object) 1);
+
+        $qb_clone = clone $qb;
+
+        $this->assertEquals((string) $qb, (string) $qb_clone);
+
+        $qb->andWhere('u.id = 1');
+
+        $this->assertFalse($qb->getQueryParts() === $qb_clone->getQueryParts());
+        $this->assertFalse($qb->getParameters() === $qb_clone->getParameters());
+    }
 }