Quick-search returns blank on search expressions such as ca_entity_labels.surname:smith

In the top right hand box for quick-search on most pages, using the search-restricted-to-attribute syntax yields a results page whose core is blank (no mention of number of results per record type at all).

To reproduce, type
ca_entity_labels:surname

or any other such terms in the quick-search box.
They get (falsely) detected by caSearchGetAccessPoints as access_points, yet caSearchGetTablesForAccessPoints will not find a match (in app/helpers/searchHelpers.php). At which point all results going into va_searches in app/controllers/find/QuickSearchController.php are null, which makes the view go empty, when it should show results if any, or at least an error message if this is deemed to be an "illegal search syntax".