FIXED (was: Fwd: Updating Inbox hangs (and I know why))

[Wolfram Fenske <Wolfram.Fenske@Student.Uni-Magdeburg.DE>]

Hello!

I have figured out a solution now: when imap-wait-for-tag discovers that the imap process has exited, it throws an exception. nnimap-request-update-info-internal catches it. If an exception occurred, nnimap-request-update-info-internal closes the current connection, opens a new one and starts itself again. If no exception occurred, it behaves as usual.

Here's what I did to imap.el, revision 1.26:

1810a1811,1812
>       (unless (memq (process-status imap-process) '(open run))
>           (throw :process-dead :process-dead))

and to nnimap.el, revision 1.29:

1119c1119
< (deffoo nnimap-request-update-info-internal (group info &optional server)
---
> (deffoo nnimap-request-update-info-internal-1 (group info &optional server)
1180a1181,1191
> (deffoo nnimap-request-update-info-internal (group info &optional server)
>   (let ((main (lambda () (nnimap-request-update-info-internal-1 
>                         group info server))))
>     (let ((result (catch :process-dead (funcall main))))
>       (if (eql result :process-dead)
>         (with-current-buffer nnimap-server-buffer
>           (nnimap-close-server server)
>           (nnimap-open-connection server)
>           (funcall main))
>       result))))
> 

This patch makes nnimap do exactly what I want it to: use the current connection if possible and open a new one if it died. Maybe my solution isn't a clean way to do that, but so far, it seems to work OK.

I still have some related problems, though. E.g. when I exit the summar buffer after longer period of time, my exception from imap.el also gets thrown but naturally isn't caught. I suppose this function has the same problem as nnimap-request-update-info-internal and could be fixed in the same way.

It's interesting that the imap process can still be alive at the beginning of nnimap-request-update-info-internal but be dead in imap-wait-for-tag, which is called by nnimap-request-update-info-internal. I guess what happens is that the server silently closes the connection, but gnutls-cli (yes, I use gnutls-cli) doesn't notice it until it tries to communicate with the server again. And when it does notice it, the imap process/gnutls-cli dies. I would like to reopen the connection directly in imap-wait-for-tag, but can't, because other functions don't realize that the process handle has changed (or something to that effect). That's why I used exceptions to do it.

What do you think? If I can help you with this issue I'd be happy to do so.

Regards
Wolfram Fenske