During the conversion of nodes to the new multilingual system in Drupal 8, the _node_mass_update_batch_process()
batch callback function was not updated properly with the rest of the surrounding code, thus missing a $langcode
parameter.
This caused an unexpected data loss situation: when a user who authored more than 10 content items (nodes) is being deleted and its content should be assigned to the Anonymous user, the content is deleted instead.
In Drupal 8.0.6, a new required $langcode
parameter has been added to _node_mass_update_batch_process()
. Even if it constitutes an API break, this solution was preferred over making the new parameter optional in order to prevent the data loss scenario.