If there are two book pages A & B, A's parent is set to B, and B's parent is set to A, it is not possible to view this book page. I believe this is because book.module goes into an infinite loop generating the breadcrumbs. This applies whether it's A & B or any number of intermediate pages that create a loop hierarchy.

It is possible to edit either page (assuming you know the /node/edit/nnn URL, the submission page still works) and break the cycle.

Suggestion: The parent popup in the book page edit form should omit the page being edited and its children.

Comments

JonBob’s picture

JonBob CreditAttribution: JonBob commented

We should use the logic of taxonomy_form_term() here to exclude the descendant book pages from the dropdown.

Steven’s picture

Steven CreditAttribution: Steven commented

Fixed in HEAD.

Anonymous’s picture

(not verified) CreditAttribution: commented