public function transform($value, MigrateExecutableInterface $migrate_executable, Row $row, $destination_property) {
list($default_value, $widget_settings) = $value;
$widget_type = $widget_settings['type'];
+ $default_value = $default_value ?: [];
+
+ // In Drupal 7, the default value for email fields is stored in the key
+ // 'email' while in Drupal 8 it is stored in the key 'value'.
+ if ($widget_type == 'email_textfield' && $default_value) {
+ $default_value[0]['value'] = $default_value[0]['email'];
+ unset($default_value[0]['email']);
+ }
$default = [];