error when connection goes down while plugged

[Dan Christensen <jdc@jhu.edu>]

I use nnimap 0.118 and pgnus 0.88 with the agent.

Sometimes my dialup connection goes down while I am plugged (often
because I absentmindedly bring it down without first doing `J j').
Once this happens, attempting to do `J j' gives the enclosed
backtrace.  The only way I have found to continue using Gnus is to
exit and restart.  Reconnecting to my ISP doesn't help.  Would it be
possible to trap this error and allow me to proceed?  I may run
into trouble with my imap groups, but I should still be able to
read my agentized news.

Dan

Signaling: (file-error "writing to process" "network is unreachable" #<process imap>)
  process-send-string(#<process imap> "6 LOGOUT
\n")
  imap-send-command-1("6 LOGOUT")
  imap-send-command("LOGOUT" nil)
  imap-send-command-wait("LOGOUT")
  imap-close(" *nnimap* chow.mat.jhu.edu")
  ad-Orig-nnimap-close-server("chow.mat.jhu.edu")
  (setq ad-return-value (ad-Orig-nnimap-close-server server))
  (let ((trace-level ...) (trace-buffer ...)) (save-excursion (set-buffer trace-buffer) (goto-char ...) (if ... ...) (insert ...)) (setq ad-return-value (ad-Orig-nnimap-close-server server)) (save-excursion (set-buffer trace-buffer) (goto-char ...) (insert ...)))
  (let (ad-return-value) (let (... ...) (save-excursion ... ... ... ...) (setq ad-return-value ...) (save-excursion ... ... ...)) ad-return-value)
  nnimap-close-server("chow.mat.jhu.edu")
  gnus-close-server((nnimap "chow.mat.jhu.edu"))
  gnus-agent-close-connections()
  gnus-agent-toggle-plugged(nil)
* call-interactively(gnus-agent-toggle-plugged)