Originally Posted by WS64
That does not work for me (and others on the German forum), at least not all the time.
What worked: When I had my 2000 shelves and then changed the settings to just have 23 the remaining 1900something empty shelves got deleted.
But, when I changed some settings on books and this resulted in empty shelves the shelves got not deleted.
My suspicion is, the driver does not check for empty shelves on the device but in the library, but I made no tests to check this since right now I have the problem that it takes very long with the new driver until Calibre has counted all my books. (More then 6 minutes, that was not that long with the old driver)
I mean that if there are books in the library that would be in a shelf this one does not get deleted on the Kobo even though no books on the Kobo do not fit in. But I may be wrong here...
Removing the empty shelve makes no reference to the calibre library. It runs two SQL statements against the database on the device. My tests just now confirmed that the removal is happening correctly.
The simple reasons I can think of for empty shelves not being removed are that metadata management is not set to automatic and the remove empty shelves option is not selected. I'm sure you have checked, but I have to make the statement.
Other than that I can't think of a reason for this to happen. So, some questions.
What change did you make to the books when you expect the shelves to be deleted? After this, you disconnected the device, let it start and then looked at the shelve list and there were some with zero books? Have you reconnected and disconnected since? Did anything change?
The only other thing I can think of is that the device is handling shelves for books and on the SD card differently than the main memory. I know I did some testing of that, but I'll have another look.