[kovidgoyal]

Originally Posted by jacr

I understand you're wary of breaking parts of Amazons functionality as we don't know what's going on there. I also understand your concern that future changes by amazon could break functionality. However:

1) I've tested the logic and scenarios I listed above and they work. I can do further testing before providing a patch, including other scenarios if you wish.

Try setting the cdetype to PDOC and see if syncing works with a uuid as ASIN

2) We're already exposed to the risk that future changes could break functionality. We're putting a random ASIN into the file, which currently enables last page sync to work- there's no guarantee this will keep working.

I'm not worried about the functionality breaking in the future, I'm worried about the side effects of ASIN collisions. Currently calibre uses a UUID of type 4. That cannot collide with an ASIN.

3) The current interaction between calibre mobi files and the kindle sharing/sync is significantly broken- of the three functions listed above only one will work at a time. This isn't intended as a criticism of calibre- it's amazon behavior. However I can't change amazon, but I can change calibre. If I've told calibre that a given non amazon book is the same as a given amazon book, then all of these functions can be made to work.

The problem is the books are explicitly not the same. A calibre MOBI is quite likely to have gone through a conversion/metadata update.

Regarding your specific concerns: a user generating MOBI files for submission to Amazon's DTP platform will not be linking the book to an amazon book using the metadata plugin, so behaviour will be as current.

Relying on users not doing something is rather optimistic. In my years of supporting calibre I have learned that if something can be done, someone will do it.

I'm not sure what the issue would be with the cross user notes?

Annotations will be keyed by a MOBI location, The location will point to different actual places in different MOBI files with the same ASIN. This will lead to strange bugs.

Why not let the user decide on whether to include the linked, via a configuration option on the mobi output? Leave it off by default, and let users who want the full sharing/sync functionality turn it on?

Because this kind of thing is likely to lead to hard to debug problems in a closed system which I will then have to answer the questions for.

I'm happy to implement, test, and maintain this. I think it would be of value to kindle users.

Feel free to run calibre from source and maintain the patch in your local copy.