Hunting crash when parking calls with SIP REFER

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@35159 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index f1b53aa..7e137d2 100644 (file)
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -11966,6 +11966,10 @@ static void *sip_park_thread(void *stuff)
        transferer = d->chan2;
        copy_request(&req, &d->req);
        free(d);
+
+       if (option_debug > 3) 
+               ast_log(LOG_DEBUG, "SIP Park: Transferer channel %s, Transferee %s\n", transferer->name, transferee->name);
+
        ast_channel_lock(transferee);
        if (ast_do_masquerade(transferee)) {
                ast_log(LOG_WARNING, "Masquerade failed.\n");
@@ -11976,6 +11980,7 @@ static void *sip_park_thread(void *stuff)
        ast_channel_unlock(transferee);
 
        res = ast_park_call(transferee, transferer, 0, &ext);
+       
 
 #ifdef WHEN_WE_KNOW_THAT_THE_CLIENT_SUPPORTS_MESSAGE
        if (!res) {
@@ -11988,9 +11993,11 @@ static void *sip_park_thread(void *stuff)
 #endif
 
        /* Any way back to the current call??? */
+       /* Transmit response to the REFER request */
        transmit_response(transferer->tech_pvt, "202 Accepted", &req);
        if (!res)       {
                /* Transfer succeeded */
+               append_history(transferer->tech_pvt, "SIPpark","Parked call on %d", ext);
                transmit_notify_with_sipfrag(transferer->tech_pvt, d->seqno, "200 OK", TRUE);
                transferer->hangupcause = AST_CAUSE_NORMAL_CLEARING;
                ast_hangup(transferer); /* This will cause a BYE */
@@ -11998,6 +12005,7 @@ static void *sip_park_thread(void *stuff)
                        ast_log(LOG_DEBUG, "SIP Call parked on extension '%d'\n", ext);
        } else {
                transmit_notify_with_sipfrag(transferer->tech_pvt, d->seqno, "503 Service Unavailable", TRUE);
+               append_history(transferer->tech_pvt, "SIPpark","Parking failed\n");
                if (option_debug)
                        ast_log(LOG_DEBUG, "SIP Call parked failed \n");
                /* Do not hangup call */
@@ -12005,7 +12013,9 @@ static void *sip_park_thread(void *stuff)
        return NULL;
 }
 
-/*! \brief Park a call */
+/*! \brief Park a call using the subsystem in res_features.c 
+       This is executed in a separate thread
+*/
 static int sip_park(struct ast_channel *chan1, struct ast_channel *chan2, struct sip_request *req, int seqno)
 {
        struct sip_dual *d;
@@ -12031,6 +12041,8 @@ static int sip_park(struct ast_channel *chan1, struct ast_channel *chan2, struct
        /* Make formats okay */
        transferee->readformat = chan1->readformat;
        transferee->writeformat = chan1->writeformat;
+
+       /* Prepare for taking over the channel */
        ast_channel_masquerade(transferee, chan1);
 
        /* Setup the extensions and such */
@@ -12045,6 +12057,8 @@ static int sip_park(struct ast_channel *chan1, struct ast_channel *chan2, struct
        /* Make formats okay */
        transferer->readformat = chan2->readformat;
        transferer->writeformat = chan2->writeformat;
+
+       /* Prepare for taking over the channel */
        ast_channel_masquerade(transferer, chan2);
 
        /* Setup the extensions and such */
@@ -12061,6 +12075,13 @@ static int sip_park(struct ast_channel *chan1, struct ast_channel *chan2, struct
                return -1;
        }
        ast_channel_unlock(transferer);
+       if (!transferer || !transferee) {
+               if (!transferer)
+                       ast_log(LOG_DEBUG, "No transferer channel, giving up parking\n");
+               if (!transferee)
+                       ast_log(LOG_DEBUG, "No transferee channel, giving up parking\n");
+               return -1;
+       }
        if ((d = ast_calloc(1, sizeof(*d)))) {
                /* Save original request for followup */
                copy_request(&d->req, req);