Migration of Annotations and Comments to 4.0 breaks page consistency

Steps to reproduce:

• download a 2.7.2 hsqldb+jetty and start it
• create a page, let's say AnnotationsMigrationTest
• add a chunk of text on that page
• create 10 annotations on the text
• add 10 comments on the page (see images attached)
• to each of the 10 comments, add a reply (see images attached)
• gracefully shutdown the 2.7.2 instance
• download latest 4.0 hsqldb+jetty
• copy the database directory content from 2.7.2 and overwrite it over the 4.0 database directory
• start the 4.0 snapshot
• import the 4.0 snapshot xar

Problem:

• go the page created previously, you will see that the replies to comment have become replies to annotations

Image attached