form collection label not correct

Fixes this symfony#6607 in 2.8 branch. See also symfony#8280

Author: stoccc

form/form_collections.rst

@@ -130,7 +130,8 @@ Notice that you embed a collection of ``TagType`` forms using the
             $builder->add('description');
 
             $builder->add('tags', CollectionType::class, array(
-                'entry_type' => TagType::class
+                'entry_type' => TagType::class,
+                'entry_options' => array('label' => false)
             ));
         }
 
@@ -286,6 +287,7 @@ add the ``allow_add`` option to your collection field::
 
         $builder->add('tags', CollectionType::class, array(
             'entry_type'   => TagType::class,
+            'entry_options'=> array('label' => false),
             'allow_add'    => true,
         ));
     }
@@ -392,9 +394,15 @@ one example:
         // get the new index
         var index = $collectionHolder.data('index');
 
+        var newForm = prototype;
+        // You need this only if you didn't set 'label' => false in your tags field in TaskType
+        // Replace '__name__label__' in the prototype's HTML to
+        // instead be a number based on how many items we have
+        // newForm = newForm.replace(/__name__label__/g, index);
+        
         // Replace '__name__' in the prototype's HTML to
         // instead be a number based on how many items we have
-        var newForm = prototype.replace(/__name__/g, index);
+        newForm = newForm.replace(/__name__/g, index);
 
         // increase the index with one for the next item
         $collectionHolder.data('index', index + 1);