#1187 Losing group assignment, multiple users

[Fredrik Fälth]

Me and some friends are sharing a Jabref database. We have quite a lot of references and have found that the "Groups" feature is a fantastic tool for using the database. However, when multiple users are working on the same file, a bug appears to erase all groups definitions.

Example how to recreate the problem:

• Create a database with at least one entry. Create some groups.
• User A and B open the same database file from a shared disk space.
• User A drags one of the entries to one of the groups and saves. The database file looks fine on his side, the new change is applied and all group assignments are still there.
• Meanwhile, user B gets a question from JabRef whether he wants to accept the changes from user A. If he accepts the changes, all group assignment will be lost. Ironically, user A still sees a file that is perfectly fine.
• User B can get back the groups by simply closing and re-opening the database file.

Early on, we thought we observed total deletion of the groups tree, but this we could not re-create it for this bug report. However, there may still be cases where deletion is possible. A lock-file mechanism would be highly desirable to avoid this uncertainty, as described in Feature request 806.
https://sourceforge.net/p/jabref/feature-requests/806/

Thanks for your time and effort!