notice: Undefined index: data in content_storage() (line 1031 of sites/all/modules/cck/content.module)

The notice was appearing on filefield fields (list and description are disabled) and has disappeared after enabling description option

the same issue few months ago #1034428: Notice: Undefined index: data in content_storage() (line 1071 of /sites/all/modules/contrib/cck/content.module).

I'm getting a slightly different message (different line number) upon posting a new node:-

Notice: Undefined index: data in content_storage() (line 1074 of /srv/bindings/ab331aab8e404f6d89add5010badaee5/code/sites/all/modules/cck/content.module).
	Notice: Undefined index: data in content_storage() (line 1074 of /srv/bindings/ab331aab8e404f6d89add5010badaee5/code/sites/all/modules/cck/content.module).
	Notice: Undefined index: data in content_storage() (line 1074 of /srv/bindings/ab331aab8e404f6d89add5010badaee5/code/sites/all/modules/cck/content.module).

I found that this change makes the message go away -- that is, there's an existing guard test, so the change makes a slight extension to that test.

diff --git a/sites/all/modules/emfield/emfield.cck.inc b/sites/all/modules/emfield/emfield.cck.inc
index 757513b..1f16ab2 100644
--- a/sites/all/modules/emfield/emfield.cck.inc
+++ b/sites/all/modules/emfield/emfield.cck.inc
@@ -114,7 +114,7 @@ function _emfield_emfield_field($op, &$node, $field, &$items, $teaser, $page, $m
   if (in_array($op, array('insert', 'update'))) {
     foreach ($items as $delta => $item) {
       // We need to manually serialize the 'data' array.
-      if(is_array($items[$delta]['data'])){
+      if(array_key_exists('data', $items[$delta]) && is_array($items[$delta]['data'])){
         $items[$delta]['data'] = serialize($items[$delta]['data']);
       }
     }