Restore may be started while a snapshot of the same profile is taken

[aryoda]

Observation

While documenting the lock file usage of BiT in v1.4.1 (currently released version as at today) I saw
that snapshot() checks if a restore is running for the same profile to avoid conflicts (esp.
when restoring directly into the original folders of the snapshot files):

backintime/common/snapshots.py

Lines 719 to 720 in 25c2115

	elif not restore_instance.check():
	logger.warning('Restore is still running. Stop backup until \

I could find not a check for a running backup ("take snapshot") in ´restore()` so IMHO it may happen that

• a new snapshot is taken in one process
• a restore for the same profile may be started then in another process

backintime/common/snapshots.py

Lines 449 to 458 in 25c2115

	instance = ApplicationInstance(
	pidFile=self.config.restoreInstanceFile(),
	autoExit=False,
	flock=True)
	if instance.check():
	instance.startApplication()
	else:
	logger.warning('Restore is already running', self)
	return

Possible Impact

• TODO to be analyzed

PS: I think this may be good issue for new BiT developers (just test by starting two instances and then try to understand the source code of the restore() function...