Does s2sync send the md5 sum to Amazon for validation?

[Vaildr]

Does s2sync send the md5 sum to Amazon for validation? And what does it do when there is a conflict?

Cheers.

[ferrix]

md5 hashes of S3 nodes are retrieved in the list operation, and compared to the current md5 of the local item.  If they differ, the item is updated. (whether that means uploaded or downloaded, depends on the direction you are sync'ing)