--- a/DataFixtures/ORM/LoadDocumentData.php	Mon Feb 27 11:45:38 2012 +0100
+++ b/DataFixtures/ORM/LoadDocumentData.php	Thu Mar 01 18:43:05 2012 +0100
@@ -38,6 +38,7 @@
         
         # create new document
         $doc_def_list = array(
+            array('title'=>'Title 0', 'description'=>'Description 0', 'tags' => null, 'categories' => array()),
             array('title'=>'Title 1', 'description'=>'Description 1', 'tags' => array('tag1', 'tag2', 'tag3', 'tag4'), 'categories' => array_values($cat_def_list)),
             array('title'=>'Title 2', 'description'=>'Description 2', 'tags' => array('tag2', 'tag3', 'tag4'), 'categories' => array($cat_def_list['cat1'], $cat_def_list['cat2'])),
             array('title'=>'Title 3', 'description'=>'Description 3', 'tags' => array('tag3', 'tag4'), 'categories' => array($cat_def_list['cat1'])),

--- a/Entity/DocumentRepository.php	Mon Feb 27 11:45:38 2012 +0100
+++ b/Entity/DocumentRepository.php	Thu Mar 01 18:43:05 2012 +0100
@@ -406,15 +406,19 @@
     public function copyTags($src_doc, $tgt_doc)
     {
         //remove the previous tags
-        foreach ($tgt_doc->getTags() as $doctag) {
-            $this->getEntityManager()->remove($doctag);
+        if(!is_null($tgt_doc->getTags())) {
+            foreach ($tgt_doc->getTags() as $doctag) {
+                $this->getEntityManager()->remove($doctag);
+            }
         }
         
         // add the new ones
-        foreach ($src_doc->getTags() as $doctag) {
-            $new_doctag = clone $doctag;
-            $new_doctag->setDocument($tgt_doc);
-            $this->getEntityManager()->persist($new_doctag);
+        if(!is_null($src_doc->getTags())) {
+            foreach ($src_doc->getTags() as $doctag) {
+                $new_doctag = clone $doctag;
+                $new_doctag->setDocument($tgt_doc);
+                $this->getEntityManager()->persist($new_doctag);
+            }
         }
         
         $tgt_doc->setManualOrder(false);

--- a/Services/DocumentService.php	Mon Feb 27 11:45:38 2012 +0100
+++ b/Services/DocumentService.php	Thu Mar 01 18:43:05 2012 +0100
@@ -66,13 +66,13 @@
         $src_doc = $doc_rep->findOneByExternalId($id_doc_src);
         if(is_null($src_doc))
         {
-            throw new Exception("cloneTags: no source doc");
+            throw new \Exception("cloneTags: no source doc");
         }
         
         $tgt_doc = $doc_rep->findOneByExternalId($id_doc_tgt);
         if(is_null($tgt_doc))
         {
-            throw new Exception("cloneTags: no target doc");
+            throw new \Exception("cloneTags: no target doc");
         }
         
         
@@ -92,6 +92,9 @@
      */
     public function addTags($doc, $tag_labels)
     {
+        if(is_null($tag_labels) || (!is_string($tag_labels) && !is_array($tag_labels)) ) {
+            return;
+        }
         // We get the DocumentTags
         $em = $this->getDoctrine()->getEntityManager();
 

--- a/Tests/Services/DocumentServiceTest.php	Mon Feb 27 11:45:38 2012 +0100
+++ b/Tests/Services/DocumentServiceTest.php	Thu Mar 01 18:43:05 2012 +0100
@@ -169,6 +169,45 @@
         
     }
     
+    
+    public function testCopyTagsEmpty()
+    {
+        $doc_service = $this->get("wiki_tag.document");
+        
+        $doc0 = $this->getDoctrine()->getRepository("CompanyBaseBundle:Document")->findOneByTitle("Title 0");
+        
+        $this->assertEquals(0,count($doc_service->getTagLabels($doc0->getId())));
+        
+        $doc1 = $this->getDoctrine()->getRepository("CompanyBaseBundle:Document")->findOneByTitle("Title 1");
+        
+        $this->assertEquals(4,count($doc_service->getTagLabels($doc1->getId())));
+        
+        $doc_service->copyTags($doc0->getId(), $doc1->getId());
+        
+        $this->assertEquals(0,count($doc_service->getTagLabels($doc1->getId())));
+        
+    }
+    
+    public function testCopyNoPersist()
+    {
+        $doc_service = $this->get("wiki_tag.document");
+        $doc1 = $this->getDoctrine()->getRepository("CompanyBaseBundle:Document")->findOneByTitle("Title 1");
+        
+        $newdoc = new \Company\BaseBundle\Entity\Document();
+        $newdoc->setTitle('a title');
+        $newdoc->setDescription('a description');
+
+        $this->getDoctrine()->getEntityManager()->persist($newdoc);
+        $this->getDoctrine()->getEntityManager()->flush();
+        
+        $doc_service->copyTags($doc1->getId(), $newdoc->getId());
+        
+        $this->getDoctrine()->getEntityManager()->flush();
+        
+        $this->assertEquals(4,count($doc_service->getTagLabels($newdoc->getId())));
+        
+    }
+    
     public function setUp()
     {
         $this->_application = new \Symfony\Bundle\FrameworkBundle\Console\Application($this->_kernel);