Significant speed increases (maybe 20% for local sessions) when dealing with directories that do not need to be updated much.
Fixed memory leak.
rdiff-backup should now run in almost constant memory (about 6MB on my system).
Enabled buffering of object transfers, so remote sessions can be 50-100%+ faster.
rdiff-backup now thinks it is running as root if the destination connection is root.
Thus rdiff-backup will preserve ownership even if it is not running as root on the source end.
If you abort rdiff-backup or it fails for some reason, it is now more robust about recovering the next time it is run (before it could fail in ways which made subsequent sessions fail also).
However, it is still not a good idea to abort, as individual files could be in the process of being written and could get corrupted.
If rdiff-backup encounters an unreadable file (or, if --change-source-perms is given, a file whose permissions it cannot change), it will log a warning, ignore the file, and continue, instead of exiting with an error.