Change record status: 
Project: 
Introduced in branch: 
8.4.x
Introduced in version: 
8.4.1
Description: 

When migrating a content entity, any null source property will now be migrated to the corresponding destination property as NULL. Previously, only non-null source properties were migrated. It's now possible to explicitly designate a destination property as empty, which will cause it to be NULL in the migrated entity. This is done with a new method on \Drupal\migrate\Row:

$row->setEmptyDestinationProperty('foo');

This will set the 'foo' destination property explicitly to NULL in the destination content entity.

Impacts: 
Module developers
Updates Done (doc team, etc.)
Online documentation: 
Not done
Theming guide: 
Not done
Module developer documentation: 
Not done
Examples project: 
Not done
Coder Review: 
Not done
Coder Upgrade: 
Not done
Other: 
Other updates done