--link-dest, update permissions w/o creating a new file

[Matt McCutchen]

On Sun, 2008-11-23 at 12:04 -0500, Matthew Monaco wrote:
> I like the behavior of first doing:
> cp -al /backup/old /backup/new
> rsync /source /backup/new
> 
> This way permissions will be updates throughout all snapshots (I really
> don't want multiple copies of my entire music collection if I decide to
> make all songs group readable... etc)
> 
> Has anyone come up with a way to do this using --link-dest?

Rsync does not support this.  The logic is that either you care about
backing up the source permissions, in which case rsync should recreate
the destination files, or you don't, in which case you shouldn't use -p
and rsync won't set the destination permissions at all.  If you really
want to preserve permissions but have them not be grounds for recreating
destination files, hack your copy of rsync or continue to use "cp -al".

Matt