Batch merge does not migrate all addresses

Reported by Eileen McNaughton , the following scenario fails on batch merge. Only the first address is present on the merged record:

'matching_primary_reverse' => array(
'contact_1' => array(
array_merge(array('location_type_id' => 'Home', 'is_primary' => 1), $address1),
),
'contact_2' => array(
array_merge(array('location_type_id' => 'Home', 'is_primary' => 1), $address1),
array_}}merge(array('location_type_id' => 'Work', 'is_primary' => 0), $address2),
),
'expected' => array(
array_merge(array('location_type_id' => 'Home', 'is_primary' => 1), $address1),
array_merge(array('location_type_id' => 'Work', 'is_primary' => 0), $address2),
),

Works as expected on the 'manual' merge screen if you choose to migrate both addresses using the tickboxes.