scp: Problem when source and destination are identical

[Markus Friedl]

On Thu, May 17, 2001 at 04:54:27PM +0200, Florian Weimer wrote:
> If the source and destination file are identical, the receiving scp
> truncates the file.  On the sending end, read() returns 0, and garbage
> is sent instead of actual data, and the receiving end puts it into the
> file, which at least confuses the users.

how should rcp/scp know that the files are identical?