[fetchmail-devel] [Bug #11797] imap_mark_seen doesn't consider expunged messages

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Bug #11797, was updated on 2007-Aug-19 01:53
Here is a current snapshot of the bug.

Project: Community Fetchmail
Category: None
Status: Open
Resolution: None
Bug Group: None
Priority: 5
Submitted by: cqrs
Assigned to : none
Summary: imap_mark_seen doesn't consider expunged messages

Details: There seems to be a bug in the imap_mark_seen function -- it doesn't take
expunged messages into account.

Here is an example. First, .fetchmailrc :

======================================================================
poll XXXXXXXXXX
  protocol IMAP
  plugin "ssh %h /usr/sbin/imapd"
  auth ssh
  mda "formail >> fetched.mail"
  keep
  flush
======================================================================

Suppose there are two messages on the server -- one old (seen) and one
new. With the config above fetchmail should expunge the first message,
then fetch the second message and mark it seen. In fact fetchmail cannot
mark the second message seen because of the wrong number.
Output of "fetchmail -v":

======================================================================
fetchmail: 6.3.8 querying XXXXXXXXXX (protocol IMAP) at Thu Aug  9 20:03:53 2007: poll started
fetchmail: running ssh %h /usr/sbin/imapd (host XXXXXXXXXX service imap)
fetchmail: IMAP< * PREAUTH [CAPABILITY IMAP4REV1 LITERAL+ IDLE NAMESPACE MAILBOX-REFERRALS BINARY UNSELECT SCAN SORT THREAD=REFERENCES THREAD=ORDEREDSUBJECT MULTIAPPEND] Pre-authenticated user YYYYYYYYYY XXXXXXXXXX IMAP4rev1 2004.352 at Thu, 9 Aug 2007 20:05:13 +0400 (MSD)
fetchmail: IMAP> A0001 CAPABILITY
fetchmail: IMAP< * CAPABILITY IMAP4REV1 LITERAL+ IDLE NAMESPACE MAILBOX-REFERRALS BINARY UNSELECT SCAN SORT THREAD=REFERENCES THREAD=ORDEREDSUBJECT MULTIAPPEND SASL-IR LOGIN-REFERRALS AUTH=LOGIN
fetchmail: IMAP< A0001 OK CAPABILITY completed
fetchmail: IMAP> A0002 SELECT "INBOX"
fetchmail: IMAP< * 2 EXISTS
fetchmail: IMAP< * 0 RECENT
fetchmail: IMAP< * OK [UIDVALIDITY 1104692132] UID validity status
fetchmail: IMAP< * OK [UIDNEXT 147861] Predicted next UID
fetchmail: IMAP< * FLAGS (\Answered \Flagged \Deleted \Draft \Seen)
fetchmail: IMAP< * OK [PERMANENTFLAGS (\* \Answered \Flagged \Deleted \Draft \Seen)] Permanent flags
fetchmail: IMAP< * OK [UNSEEN 2] first unseen message in /var/spool/mail/YYYYYYYYYY
fetchmail: IMAP< A0002 OK [READ-WRITE] SELECT completed
fetchmail: IMAP> A0003 SEARCH UNSEEN NOT DELETED
fetchmail: IMAP< * SEARCH 2
fetchmail: IMAP< A0003 OK SEARCH completed
2 messages (1 seen) for YYYYYYYYYY at XXXXXXXXXX.
skipping message YYYYYYYYYY@XXXXXXXXXX:1 flushed
fetchmail: IMAP> A0004 STORE 1 +FLAGS (\Seen \Deleted)
fetchmail: IMAP< * 1 FETCH (FLAGS (\Seen \Deleted))
fetchmail: IMAP< A0004 OK STORE completed
fetchmail: IMAP> A0005 EXPUNGE
fetchmail: IMAP< * 1 EXPUNGE
fetchmail: IMAP< * 1 EXISTS
fetchmail: IMAP< * 0 RECENT
fetchmail: IMAP< A0005 OK Expunged 1 messages
fetchmail: IMAP> A0006 FETCH 1 RFC822.SIZE
fetchmail: IMAP< * 1 FETCH (RFC822.SIZE 939)
fetchmail: IMAP< A0006 OK FETCH completed
fetchmail: IMAP> A0007 FETCH 1 RFC822.HEADER
fetchmail: IMAP< * 1 FETCH (RFC822.HEADER {933}
reading message YYYYYYYYYY@XXXXXXXXXX:2 of 2 (933 header octets)
fetchmail: IMAP< )
fetchmail: IMAP< A0007 OK FETCH completed
fetchmail: IMAP> A0008 FETCH 1 BODY.PEEK[TEXT]
fetchmail: IMAP< * 1 FETCH (BODY[TEXT] {6}
 (6 body octets)fetchmail: IMAP< )
fetchmail: IMAP< A0008 OK FETCH completed
 not flushed
fetchmail: IMAP> A0009 STORE 2 +FLAGS (\Seen)
fetchmail: IMAP< A0009 BAD Bogus sequence in STORE: Sequence out of range
fetchmail: IMAP> A0010 LOGOUT
fetchmail: IMAP< * BYE XXXXXXXXXX IMAP4rev1 server terminating connection
fetchmail: IMAP< A0010 OK LOGOUT completed
fetchmail: client/server synchronization error while fetching from YYYYYYYYYY@XXXXXXXXXX
fetchmail: 6.3.8 querying XXXXXXXXXX (protocol IMAP) at Thu Aug  9 20:03:58 2007: poll completed
fetchmail: Query status=7 (ERROR)
fetchmail: normal termination, status 7
======================================================================

When there are more messages on the server wrong messages would be marked
seen before fetchmail fail. These messages will be lost on the next run.
Even worse, some IMAP servers happily allow wrong message numbers in STORE
command. In such cases a user will not even see any error message.

Adding "expunge 0" to config mitigates the problem. And the following 
patch seems to solve it:

======================================================================
diff -urN fetchmail-6.3.8.orig/imap.c fetchmail-6.3.8/imap.c
--- fetchmail-6.3.8.orig/imap.c 2006-12-16 03:34:38.000000000 +0300
+++ fetchmail-6.3.8/imap.c      2007-08-08 15:37:10.000000000 +0400
@@ -1239,6 +1239,9 @@
 static int imap_mark_seen(int sock, struct query *ctl, int number)
 /* mark the given message as seen */
 {
+    /* expunges change the fetch numbers */
+    number -= expunged;
+
     (void)ctl;
     return(gen_transact(sock,
        imap_version == IMAP4
======================================================================

Tested on fetchmail 6.3.8.

P.S. Thanks for the great program.


For detailed info, follow this link:
http://developer.berlios.de/bugs/?func=detailbug&bug_id=11797&group_id=1824