commit fbcb294ce6efbb170b9dea8dad978515a7510660
Author: Francesco Placella <plach.git@psegno.it>
Date:   Tue Dec 9 15:49:05 2014 +0100

    Fixed fatal

diff --git a/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorageSchema.php b/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorageSchema.php
index aee3861..5cf3364 100644
--- a/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorageSchema.php
+++ b/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorageSchema.php
@@ -1622,7 +1622,9 @@ protected function getDedicatedTableSchema(FieldStorageDefinitionInterface $stor
       // Properties marked as 'required' do not allow NULL values, others do.
       // Note: this works because dedicated tables contain no row for empty
       // fields.
-      $data_schema['fields'][$real_name]['not null'] = $properties[$column_name]->isRequired();
+      if (isset($properties[$column_name])) {
+        $data_schema['fields'][$real_name]['not null'] = $properties[$column_name]->isRequired();
+      }
     }
 
     // Add indexes.