[bug-mailutils] attribute_set_seen() in mailbox.c:mailbox_flush, why?

[Andy]

Hi All,

I want to copy (only new) messages from a source mailbox to a destination 
mailbox, adding a unique ID in the
header whilst copying, eg. copying only new email from a POP (or IMAP) server 
to a local mailbox.
I was making the mistake of flushing the mailbox (If I did not use flush, the 
new header field was
not written to disk), but all messages are set to "seen" in flush(). Is this 
right?
After reading this email:
  http://lists.gnu.org/archive/html/bug-mailutils/2003-06/msg00025.html
(this is no good if mailbox_flush(mbox, 1); sets the status back to
'seen", no?)
I now use mailbox_expunge() or mailbox_save_attributes(), and not
flush().

Is the attached code the right way for doing what i want, as described
above?

Also, can anyone say why the "seen" attribute is set in the mailbox flush 
function?
  mailutils-0.6/mailbox/mailbox.c:mailbox_flush()
  attribute_set_seen (attr);  (line 218)

thanxs for any help, i attach the code, below is the output.
Andy

$ f=tmp/mbox; >$f; ./mbtest pop://username:address@hidden $f;
grep -e "^From " -e Status -e XXX $f
1, 1
1 uild is [a363d598644ac93c784619c010b1efa5] src status is [(NO STATUS)]
dst status is [(NO STATUS)]
2, 2
2 uild is [1b6f2d336af77b35d22f593e3ff085a3] src status is [(NO STATUS)]
dst status is [(NO STATUS)]
3, 3
3 uild is [b8af9be1a0d798c1dd4e3a0dc9c30aa6] src status is [(NO STATUS)]
dst status is [(NO STATUS)]
>From xxxxxxxxxxxxx Mon Dec 27 19:21:10 2004
X-XXX: Testing
>From yyyyyyyyyyyyy Mon Dec 27 19:21:11 2004
X-XXX: Testing
>From address@hidden Mon Dec 27 19:21:13 2004
X-XXX: Testing
Status: R

mbtest.c
Description: Text Data