Thread:Project:Support desk/Check on edit save if page is new?/reply (4)

rev_parent_id only is the name of the DB field, not a method of the $revision object. There are two functions, which might help: $revision->getParentId should return the revision number of the parent or null, if none is present. $revision->getPreviousRevisionId in contrast should always return an integer, that is 0 for the first revision.