Is there any documentation on exactly how "M"erge works?

[sparker]

I've searched the Calibre documentation and this forum for exactly how merge works, but have been unable to find any information.

I understand that the intent is to select one book, then a second, and the metadata from the "first selected books wins". But this doesn't always seem to work right. If some fields are empty in the first and some are empty in the second, they often will do what I think should happen (the empty fields in the first book will be populated with the fields from the second).

What if there are metadata conflicts. I often see cases where there is different metadata in title, author, series between the books, and sometimes it appears that Calibre is keeping the first book's metadata, sometimes it's replacing the first book metadata with the second books metadata.

Is there any detailed documentation on exactly how Calibre decides to merge metadata (and book formats) based on which of the 3 merge options I chose?

TIA for any links to docs the community can provide!

Steve

[kovidgoyal]

There is no documentation beyond whats in the dialogs, That documentation tells you the algorithm. If you feel it is not being followed, then by all means open a bug report, attach the metadata.db file from the library and provide a set of steps to re-create the problem and I will take a look.