Be sure prev struct is built properly (bug #2581)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@3926 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/channels/chan_zap.c b/channels/chan_zap.c
index f900059..88ccaaf 100755 (executable)
--- a/channels/chan_zap.c
+++ b/channels/chan_zap.c
@@ -6556,6 +6556,7 @@ static struct zt_pvt *mkintf(int channel, int signalling, int radio, struct zt_p
                        if (working->channel > tmp->channel) {
                                tmp->next = *wlist;
                                tmp->prev = NULL;
+                               (*wlist)->prev = tmp;
                                *wlist = tmp;
                        } else {
                        /* go through all the members and put the member in the right place */