We’re going to post a work with two chapters and then delete the first chapter:
Post > New Work
Fill in required fields and, on the way down, check "This work has multiple chapters." You don't have to do anything special in this field.
Follow the "Add Chapter" link
Fill in required fields
Follow the "Previous Chapter" link to return to Chapter 1
Follow the "Edit Chapter" link
Press "Delete Chapter" and press "OK" to confirm deletion
Many things! But I'm reasonably sure they all relate to what's going on at the database level, which is the Chapter object's position attribute remains position: 2. Here, let me show you:
Now, the practical, user-facing consequences of this are:
The title of the remaining chapter says "Chapter 2"
If you follow the "Edit Chapter" link on the chapter, you will see it listed as Chapter Number 2 of ? on the form, and the chapter text will appear in the Chapter Text field
If you follow the "Edit" link to edit the work, you will see the chapter's text in the Work Text field, which usually only happens for Chapter 1 of a work (until Chapter 2 is posted, then the text is no longer there)
The Chapter should be position: 1
The chapter title should be “Chapter 1”
Following the "Edit Chapter" link should show the chapter as Chapter Number 1 of ?
Possibly related to somehow?
Also, if you post a new chapter, the new one ends up as Chapter 1, both in terms of title and position.