Acquia Drupal update data not returned from Acquia servers

acquia_agent modifies the updated status of Drupal core in acquia_agent_update_status_alter(). On my site, the module contacts the Acquia endpoint successfully and returns some $subscription data to acquia_agent_update_status_alter(), but $subscription['update'] is an empty array. The empty array passes the isset() check on line 376 and Acquia Drupal's update status gets set to 'unknown' on line 377.

This causes Drupal core to appear in yellow on admin/reports/updates, with no recommended version. Security update emails get sent even though all modules are up-to-date.

If I change isset($subscription['update']) to !empty($subscription['update']) the more informative "No information available from Acquia Insight" message appears inside the Acquia Drupal block on the updates page.

So I guess this is two issues:

• Return Acquia Drupal update information from nspi.acquia.com
• Change the isset() on line 376 to !empty() to handle case where $subscription['update'] is an empty array.