Issue: Chapters Missing from Table of Contents after Switching Types

We have a chapter that is a regular page attached to a book. Say we later edit the chapter and change it to a book-type so that it can contain sub-chapters. Any sub-chapters added to this new book will not appear in the table of contents for the outer-most book.

The problem is that when new books are created (whether as a new page or by activating the type), it is assumed that it is not already part of another book. This assumption generates an incorrect parent/child relationship between the two books which becomes noticeable by missing sub-entries in the table of contents.

This is fixed in the next release. Affected books will have their relations rebuilt by the upgrade script.