SQL error: Views field broken with relation: Workflow current: State name

In current (2.8) dev.

How to reproduce

* Using workflow_field, not workflow_node
* Add field Workflow current: State name on a relation(!)

Result: Erroneously empty field content.

Analysis

This SQL join

LEFT JOIN workflow_node_history node_field_data_field_opencsa_delivery_workflow_node_current ON ( SELECT max(hid) FROM workflow_node_history
                            where nid = node.nid
                            and   sid != old_sid ) = node_field_data_field_opencsa_delivery_workflow_node_current.hid

uses node.nid where something like relation_node.nid should have been.