[rdiff-backup-users] --override-chars-to-quote bug fixed and default behaviour change

[Oliver Mulatz]

On 2009-01-05 Oliver Mulatz wrote:

> Another issue: there's a bug (RDB aborts) in '--override-chars-to-quote'
> functionality, (I require for cross-platform filesystem compatibility).
>
> It hits each time "--override-chars-to-quote" is used, even with empty
> set ('') for keeping capital chars from being escaped.
>
> The exact error including trace was also posted to the ML on Oct'08 by EliW:
> 
http://www.backupcentral.com/phpBB2/two-way-mirrors-of-external-mailing-lists-3/rdiff-backup-23/probleme-with-rdiff-on-smbfs-92963/#287692

I fixed it, but would like to go deeper.

Now is a good time to discuss a default behaviour change, since the
'--override-char-to-quote' (=> OCTQ) option *never* worked, so users
will not be surprised and no scripts need to be changed.

Currently, and what I have read on the mailing-list, the OCTQ-option must
be provided ON EACH commandline issued when used initially to create a backup
mirror, also for restores. This is non-intuitive IMO, a more sensible approach
would be:

1. if no commandline OCTQ option is provided when a backup mirror is created,
   use FS auto-detected chars to quote (already doing so now)
2. if a backup mirror was started with OCTQ, this is assumed valid unless
   otherwise notice/overridden (default behaviour needs to be changed for this,
   but breaks nothing AFAICT)
3. if the OCTQ really must be changed after creation of backup mirror with
   initial OCTQ set, coupling with '--force' option would be naturally most
   intuitive, otherwise shows error-message hinting about this
   => so anybody knows this is a potential 'risky/deep' change, along the line
   of overwriting already existing directories when doing a RDB restore, ...

This has the benefit of being more intuitive, it's no problem to forget
about the required char-set once a mirror is set up and not required
for each action/restore.

When there are no objections to this change, I create the patches for this
against the 1.3 development-release.

Cheers,
Oliver