put in proper fix for issue #7294 instead of the broken partial fix that was committed, and thereby also fix issue #7438

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.2@41716 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -12931,21 +12931,25 @@ static struct ast_rtp *sip_get_vrtp_peer(struct ast_channel *chan)
 static int sip_set_rtp_peer(struct ast_channel *chan, struct ast_rtp *rtp, struct ast_rtp *vrtp, int codecs, int nat_active)
 {
 	struct sip_pvt *p;
+	int changed = 0;
 
 	p = chan->tech_pvt;
 	if (!p) 
 		return -1;
 	ast_mutex_lock(&p->lock);
 	if (rtp)
-		ast_rtp_get_peer(rtp, &p->redirip);
+		changed |= ast_rtp_get_peer(rtp, &p->redirip);
 	else
 		memset(&p->redirip, 0, sizeof(p->redirip));
 	if (vrtp)
-		ast_rtp_get_peer(vrtp, &p->vredirip);
+		changed |= ast_rtp_get_peer(vrtp, &p->vredirip);
 	else
 		memset(&p->vredirip, 0, sizeof(p->vredirip));
+	if (codecs && (p->redircodecs != codecs)) {
 		p->redircodecs = codecs;
-	if (codecs && !ast_test_flag(p, SIP_GOTREFER)) {
+		changed = 1;
+	}
+	if (changed && !ast_test_flag(p, SIP_GOTREFER)) {
 		if (!p->pendinginvite) {
 			if (option_debug > 2) {
 				char iabuf[INET_ADDRSTRLEN];

include/asterisk/rtp.h

@@ -96,7 +96,7 @@ struct ast_rtp *ast_rtp_new_with_bindaddr(struct sched_context *sched, struct io
 
 void ast_rtp_set_peer(struct ast_rtp *rtp, struct sockaddr_in *them);
 
-void ast_rtp_get_peer(struct ast_rtp *rtp, struct sockaddr_in *them);
+int ast_rtp_get_peer(struct ast_rtp *rtp, struct sockaddr_in *them);
 
 void ast_rtp_get_us(struct ast_rtp *rtp, struct sockaddr_in *us);
 

rtp.c

@@ -1041,11 +1041,17 @@ void ast_rtp_set_peer(struct ast_rtp *rtp, struct sockaddr_in *them)
 	rtp->rxseqno = 0;
 }
 
-void ast_rtp_get_peer(struct ast_rtp *rtp, struct sockaddr_in *them)
+int ast_rtp_get_peer(struct ast_rtp *rtp, struct sockaddr_in *them)
 {
+	if ((them->sin_family != AF_INET) ||
+	    (them->sin_port != rtp->them.sin_port) ||
+	    (them->sin_addr.s_addr != rtp->them.sin_addr.s_addr)) {
 		them->sin_family = AF_INET;
 		them->sin_port = rtp->them.sin_port;
 		them->sin_addr = rtp->them.sin_addr;
+		return 1;
+	}
+	return 0;
 }
 
 void ast_rtp_get_us(struct ast_rtp *rtp, struct sockaddr_in *us)