Data loss : conflict between onlyoffice and nextcloud desktop client

[tomdereub]

Step to reproduce :

• open an xlsx file on nextcloud web with onlyoffice, and at the same time on a computer on excel, the file is synced with the nextcloud desktop client
• make some modifications on both sides
• save and close the file on the computer, close the tab on onlyoffice
• after a sync with the desktop client, the file is the one modified on onlyoffice, and the modifications made on excel are lost. The nextcloud desktop client replace the version without seeing the conflict.

Nextcloud desktop client should create a conflict to avoid data loss.

Nextcloud server 29.0.10, onlyoffice connector 9.5.0, onlyoffice document server 8.1.1.26.

[tomdereub]

I made some more tests :

• if I close first the onlyoffice tab, or onlyoffice has first saved the file, the nextcloud desktop client shows a conflict
• if I close first the excel file, then onlyoffice erases nextcloud desktop client modifications.

So onlyoffice should be able to see a conflict if the nextcloud's file has changed between 2 savings.
Maybe there's a workaround with file locks, but it seems that onlyoffice doesn't support nextcloud lock for the moment ?