FYI a user of ours encountered this recently and we came to the conclusion it's a Thunderbird bug. An edited conversion I had with Bron is below.
Checking the Thunderbird bugzilla, I see multiple reports of this. In particular a bug that was supposedly fixed in 2010 seems to have recently re-appeared for some people. https://bugzilla.mozilla.org/show_bug.cgi?id=592633 See comments near the bottom of that bug. Someone has opened a new bug. https://bugzilla.mozilla.org/show_bug.cgi?id=1089351 I see an old bug similarly related to this. https://bugzilla.mozilla.org/show_bug.cgi?id=529618 There's this comment near the bottom: --- Workaround was fortunatly found accidentally : Double click of IMAP folder. When IMAP folder was double clicked at folder pane, expand button automatically appeared and subfolder was automatically shown when subfolder exists. --- Can you check if that works for you? Rob ----- me: It appears LSUB and LIST (SUBSCRIBED) are only returning \HasChildren if there's a subscribed child mailbox, not if the actual mailbox has children. That seems wrong... Example in a users mailbox. . list INBOX.x.y.2015 * * LIST (\HasChildren) "." INBOX.x.y.2015 ... many more sub-folders ... . lsub INBOX.x.y.2015 * * LSUB () "." INBOX.x.y.2015 . OK Completed (0.010 secs 2 calls) . list (subscribed) INBOX.x.y.2015 * * LIST (\Subscribed) "." INBOX.x.y.2015 . OK Completed (0.010 secs 2 calls) bron: My reading of those is that they're correct. HasChildren actually only needs to be calculated in two cases: 1) it's been explicitly asked for with a RETURN option in LIST-EXTENDED 2) the expression matches a non-existent intermediate folder, but not its existent children. Otherwise it's nice to do, but not required. In particular, both LSUB and RETURN SUBSCRIBED only iterate the subscriptions database - so they don't know about children. We don't calculate them unless explicitly requested. I really do think it's a Thunderbird bug. me: . list INBOX.x.y.2015 * return (children) * LIST (\HasChildren) "." INBOX.x.y.2015 . list (subscribed) INBOX.x.y.2015 * return (children) * LIST (\Subscribed \HasChildren) "." INBOX.x.y.2015 Yeah, I think you might be right, the lack of both \HasChildren or \HasNoChildren shouldn't imply anything. On Wed, 13 Apr 2016, at 01:05, Giles Malet via Cyrus-devel wrote: > Before I head off to read RFCs, and try to understand what Cyrus is doing > and Thunderbird, and what is going wrong, I just wanted to ask if anyone > already knows the answers. Specifically, using LIST-EXTENDED, should a > mail client be able to determine which folders are subscribed to, and if > so why is Cyrus apparently not returning that information? Conceivably TB > is doing it wrong though. And if TB is trying to set a \Subscribed flag > on a folder, should that be updating Cyrus's list of subscriptions? > > Anyhow, I'll see if I can get some traces of what's going on, and see if > that's what should be going on. > > Thanks, > g -- Rob Mueller r...@fastmail.fm
