PHP notice after submitting edit page

Testing the 7.x latest git version here, ran into this when submitting the edit page of "Welcome to Spark!" "Every field" type node. It happens when there is more than one taxonomy term but not if there is zero or one terms.

Notice: Array to string conversion in array_diff_assoc() (line 369 of /var/www/html/includes/entity.inc). =>

17: array_diff_assoc() (Array, 1 element)
16: DrupalDefaultEntityController->cacheGet() (Array, 2 elements)
15: TaxonomyTermController->cacheGet() (Array, 2 elements)
14: DrupalDefaultEntityController->load() (Array, 2 elements)
13: entity_load() (Array, 2 elements)
12: taxonomy_term_load_multiple() (Array, 2 elements)
11: taxonomy_autocomplete_validate() (Array, 2 elements)
10: _form_validate() (Array, 2 elements)
9: _form_validate() (Array, 2 elements)
8: _form_validate() (Array, 2 elements)
7: drupal_validate_form() (Array, 2 elements)
6: drupal_process_form() (Array, 2 elements)
5: drupal_build_form() (Array, 2 elements)
4: drupal_get_form() (Array, 2 elements)
3: node_page_edit() (Array, 2 elements)
2: call_user_func_array() (Array, 1 element)
1: menu_execute_active_handler() (Array, 2 elements)
0: main() (Array, 2 elements)