[imp] excessive "select inbox"

[Joseph Brennan]

Tossing this out in case it rings a bell with anybody...



We have one user (out of tens of thousands) who can't open mail in
folders other than inbox.

We have a cyrus imap server. I set it to record sessions for this
user and for me.

I can see from my own session that for every screen, IMP does a
SELECT foldername, the relevant command(s), and UNSELECT.  Then IMP
pauses and sends no commands until I click something on my screen.

For this one user, as soon as it does UNSELECT, it does SELECT inbox.
Example of the timing (unix seconds), from the cyrus log:

1298580536  select inbox, get header info, etc
1298580537  unselect
1298580540  select sent-mail, get header info, etc
1298580540  unselect
1298580541  select inbox, get header info, etc
1298580542  unselect
1298580545  select inbox, get header info, etc
1298580546  unselect
1298580546  select inbox, get header info, etc
1298580548  unselect

She sees the list of messages in sent-mail, and it stays there.
(So IMP is doing SELECT inbox, getting info to redraw the screen,
but not redrawing the screen.)  When she clicks on any message in
the list, then the screen re-draws to show the list of messages
in inbox, and she sees the error "Requested message not found".

In the cyrus log I expected to find a failed FETCH command, but
it's not there.  There is no evidence that IMP did FETCH, which
suggests that IMP itself decided "Requested message not found",
but on what basis I don't know.

I see a detailed explanation of a "Requested message not found" case
<http://lists.horde.org/archives/imp/Week-of-Mon-20050314/041351.html>
but the problem there was that the user's session was getting load
balanced to two IMP servers.  That was not the case here.  Her IMP
session stayed on one host.

Since it is one user, I suspect something in the preferences makes
IMP repeatedly SELECT inbox, but I can't find it.  In fact her
preferences are vanilla except to sort by arrival descending, and
choosing her name.  I made my account sort by arrival descending
and as expected I do not get the repeated SELECTs.

Notice that even when she is reading inbox, every time it finishes
and does UNSELECT, it immediately does SELECT inbox again, more than
once.  Not normal.  All it does is get the header info it would need
to show the list of messages.  However at least she is able to open
messages in inbox.