Manual:Null revision
A null revision is a special type of page revision that occurs only with specific types of actions performed on pages or their revisions. In the database, the null revision has the same revision.rev_text_id as its parent. It causes the log event to be displayed in the page history.
A null revision may be created through RevisionStore::newNullRevision() or PageUpdater::setForceEmptyRevision().
Actions that create null revisions
[edit]- Imports
- Page moves
- Page protection, unprotection, or changing protection level
Actions that do not create null revisions
[edit]In these cases, revision rows are created with new ids.
- Changing visibility of deletions (RevisionDelete)
- Merges
- Page deletions
- Page restorations
- Patrol events