2-way sync

[michabbs]

The README misses very important information: "How to SAFELY perform 2-way synchronization?".

For example - if I start periodically from cron such script:

#!/bin/sh
dropbox-api-command sync dropbox:/ ~/Dropbox -d
dropbox-api-command sync ~/Dropbox dropbox:/ -d

It seems to work fine, but... is it really safe? What can happen if one file was changed on both sides simultaneusly? Is there any race condition here possiible here? What if I add a new file when the synchronization is already half-way? Will the script do something reasonable then? Are there any disadvantages/dangers of running such script from cron without human supervision?