Suppose there are three repo: A, B and transfer, transfer is a webdav remote.

1. I add file-1 to A, do a sync content, file-1 is sent to transfer.
2. I add file-2 to A, do a sync content, I expect only file-2 to be sent to transfer, but file-1 is sent another time. 

How can I avoid that?

Does other special remote like the rsync special remote has this issue?
