zodbsync should check file ownerships before writing the filesystem repo #147
Description
Is your feature request related to a problem? Please describe.
Some people accidentally run sudo zodbsync or zodbsync while being logged in as the wrong user, but with enough permissions to overwrite files.
The consequence being that, should the filesystem be a git repository, with all the ownerships mixed up, git commands will refuse to work and other mishaps follow.
Describe the solution you'd like
When zodbsync starts, it could check if the file ownerships in the file system really correspond to the user executing it. It could refuse to run in that case, or allow forcing to run with a --force flag. I don't believe there is a practical reason to force, though, so I believe the opt-out can be dropped.
Describe alternatives you've considered
Right now, people just watch their step. This suggestion is just to improve stability.
Additional context
This is related to T290366 at PerFact.