[ownedbycats]

Unexpected behaviour. Having difficulty replicating it because I'm not sure of the exact sequence of actions, but it was roughly this:

1. While a search was active, I added a new book.
2. While editing the book, I clicked on the Category Editor (I believe it saved changes) for publisher and merged it with another.
3. At some point (either while the category editor was open or right after closing it) I noticed the book details pane in the background had changed to a different book.
4. Then I got an error similar to 'no such book id'.