CORRECT PATCH Re: sync_client bails when encountering a deleted message

[John Capo]

Quoting Ken Murchison (murch at andrew.cmu.edu):
> Ken Murchison wrote:
> >Obviously, the chances of header_size being 0xdeadbeef is remote, but it 
> >is possible.  Would it make more sense to use ULONG_MAX as the "failure 
> >size"?
> 
> Or better yet, how about just using 0 (zero)?  IIRC, RFC2822 stipulates 
> that the message header has to be non-zero (Date and From are mandatory)

I have seen zero size messages created with IMAP uploads from desktop
clients.  This is probably a bug elsewhere.  I do not know if the
zero size messages were replicated.

Sending more than one magic number would be the safest way. The
value of the second magic number could be used to signal other
conditions if needed.  I can't imagine what that would be other
than aborting the upload.  Two ULONG_MAX is a row can't be a valid
message.