imap/2079: segfault with imap host completion

[New Mutt PR <cb@xxxxxxxx>]

>Number:         2079
>Notify-List:    329442@xxxxxxxxxxxxxxx
>Category:       imap
>Synopsis:       segfault with imap host completion
>Confidential:   no
>Severity:       normal
>Priority:       medium
>Responsible:    mutt-dev
>State:          open
>Keywords:       
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Sep 22 03:44:49 +0200 2005
>Originator:     Nico Golde
>Release:        
>Organization:
>Environment:
>Description:
Original report:

Hi,
please change in imap.c the line
for (conn = mutt_socket_head (); conn->next; conn = conn->next)
to
for (conn = mutt_socket_head (); conn && conn->next; conn = conn->next)

Otherwise mutt segfaults if mutt_socket_head return NULL
which happens on some systems.
>How-To-Repeat:
% mutt
cimap://<TAB>
>Fix:
Unknown
>Add-To-Audit-Trail:

>Unformatted: