[DDC-1835] Fix cloning persistent collections.

lib/Doctrine/ORM/PersistentCollection.php

@@ -778,14 +778,13 @@ final class PersistentCollection implements Collection
      */
     public function __clone()
     {
-        $this->initialize();
-
-        $this->owner = null;
-
         if (is_object($this->coll)) {
             $this->coll = clone $this->coll;
         }
 
+        $this->initialize();
+
+        $this->owner    = null;
         $this->snapshot = array();
 
         $this->changed();

tests/Doctrine/Tests/ORM/Functional/PersistentCollectionTest.php

@@ -0,0 +1,98 @@
+<?php
+
+namespace Doctrine\Tests\ORM\Functional;
+
+use Doctrine\Common\Persistence\PersistentObject;
+
+/**
+ */
+class PersistentCollectionTest extends \Doctrine\Tests\OrmFunctionalTestCase
+{
+    protected function setUp()
+    {
+        parent::setUp();
+        try {
+            $this->_schemaTool->createSchema(array(
+                $this->_em->getClassMetadata(__NAMESPACE__ . '\PersistentCollectionHolder'),
+                $this->_em->getClassMetadata(__NAMESPACE__ . '\PersistentCollectionContent'),
+            ));
+        } catch (\Exception $e) {
+
+        }
+        PersistentObject::setObjectManager($this->_em);
+    }
+
+    public function testPersist()
+    {
+        $collectionHolder = new PersistentCollectionHolder();
+        $content = new PersistentCollectionContent('first element');
+        $collectionHolder->addElement($content);
+
+        $this->_em->persist($collectionHolder);
+        $this->_em->flush();
+        $this->_em->clear();
+
+        $collectionHolder = $this->_em->find(__NAMESPACE__ . '\PersistentCollectionHolder', $collectionHolder->getId());
+        $collectionHolder->getCollection();
+
+        $content = new PersistentCollectionContent('second element');
+        $collectionHolder->addElement($content);
+
+        $this->assertEquals(2, $collectionHolder->getCollection()->count());
+    }
+
+}
+
+/**
+ * @Entity
+ */
+class PersistentCollectionHolder extends PersistentObject
+{
+    /**
+     * @Id @Column(type="integer") @GeneratedValue
+     * @var int
+     */
+    protected $id;
+
+    /**
+     * @var \Doctrine\Common\Collections\Collection
+     * @ManyToMany(targetEntity="PersistentCollectionContent", cascade={"all"})
+     */
+    protected $collection;
+
+    public function __construct()
+    {
+        $this->collection = new \Doctrine\Common\Collections\ArrayCollection();
+    }
+
+    /**
+     * @param PersistentCollectionContent $element
+     */
+    public function addElement(PersistentCollectionContent $element)
+    {
+        $this->collection->add($element);
+    }
+
+    /**
+     * @return \Doctrine\Common\Collections\Collection
+     */
+    public function getCollection()
+    {
+        return clone $this->collection;
+    }
+
+}
+
+/**
+ * @Entity
+ */
+class PersistentCollectionContent extends PersistentObject
+{
+
+    /**
+     * @Id @Column(type="integer") @GeneratedValue
+     * @var int
+     */
+    protected $id;
+
+}