Unexpected behaviour of the Calibre "e-book editor"

[WalterWalter]

Unexpected behaviour of the Calibre "e-book editor"

Using "Edit book" changes a book even if you never edited anything by automatically exchanging AND saving all metadata info in the book with the information in the calibre database. I understand that the principle of a database is: "The database is alwaxs right", so if there is a conflict between metadata in the book file , the metadata.opf file in the directory of the bookfile and the info iun the calibre database, then the info in the calibre database should rule supreme (unless you rebuild the databose from all the *.opf files).

But changing AND saving the .epub file without letting the user know or asking can lead to unexpected effects. Under "Add books" via "Control the adding of books" you can choose wether to read netadata from the book rather than the file name. If you have not ticked this option, calibre will not read any metadata in the book and use the filename to usually determine auther titel and series. If you read in a book like this, additional metadata information will still be in the epub bookfile, as can be veriefied by either unzipping the epub file or right clicking on the bookfile and using the e-book editor from calibre directly. Opening and closing the book via right clicking and choosing the editor to open it and closing without changing it, will not change the file nor the date of "last changed". If, however, one does the same thing by clicking on the "Edit book" icon in the main calibre program, the editor will first replace all existing metadata information in the book with the information from the calibre database and then SAVE the file immediatly (as can be verified by the changing of the "last changed" date of the book file and only then display the book for editing to the user.

Note: This means if you just open a book for editing and close it without changes, the editor will always have changed the book without giving any indication.
Note: By using the editor from inside the main calibre program you have no chance to have a look at the original metadata in the book, noreover, this data is lost, unless you keep a copy of the original file that you read into calibre.

This has nothing to do with the act of "Polishing a book" or using "Embed metadata", because there explicitly you want to/can choose to update the metadata in the bookfile.

This problem also exists, when editing books. If you use the editor to change anything in the .opf file of the book, then the changes will be saved in the ebook file, but when opening it the next time with the editor these changes will be automatically overwritten.

As I said, the calibre database should rule supreme, but even a supreme ruler should be nice enough to warn of conflicts. So in case of the editor, I would suggest a warning/dialog along the line: "The mnetadata in the bookfile is not consistent with the metadata in calibre, what do you want to do?", and give the user some choices.

I also realize, that one could consider the current behavious of the editor a feature, because it ensures data consitency. But then it should be prominently mentioned in the manual. There is no mentioning of the automatic replacement of the metadata at startup of the editor.


Just for info: I am using the 64-bit version of Calibre Portable on a Windows 10 PC. My Version of calibre is 5.36 with all plugins updated.

[kovidgoyal]

If you dont want metadata updated when editing a book, use the option to turn it off under calibre integration in the editor preferences.

[WalterWalter]

Thank you, I did not know about this option, I turned it off, now it works perfectly.