TT#14008 fix handling of possible NULL rtcp_sibling

closes #1302

Change-Id: I000337734400cf3a5b63fc5d51e9fd220be06c68

daemon/call.c

@@ -1268,7 +1268,7 @@ static int __init_streams(struct call_media *A, struct call_media *B, const stru
 			PS_CLEAR(a, RTCP);
 		else {
 			if (MEDIA_ISSET(A, ECHO) || MEDIA_ISSET(A, BLACKHOLE))
-				__add_sink_handler(&a->rtcp_sinks, a->rtcp_sibling);
+			{ /* RTCP sink handler added below */ }
 			else
 				__add_sink_handler(&a->rtcp_sinks, b);
 			PS_SET(a, RTCP);
@@ -1283,8 +1283,11 @@ static int __init_streams(struct call_media *A, struct call_media *B, const stru
 		assert(la != NULL);
 		a = la->data;
 
-		if (MEDIA_ISSET(A, ECHO) || MEDIA_ISSET(A, BLACKHOLE))
+		if (MEDIA_ISSET(A, ECHO) || MEDIA_ISSET(A, BLACKHOLE)) {
 			__add_sink_handler(&a->rtcp_sinks, a);
+			if (MEDIA_ISSET(A, RTCP_MUX))
+				__add_sink_handler(&ax->rtcp_sinks, a);
+		}
 		else
 			__add_sink_handler(&a->rtcp_sinks, b);
 		PS_CLEAR(a, RTP);

daemon/media_socket.c

@@ -1694,7 +1694,8 @@ static void media_packet_rtcp_demux(struct packet_handler_ctx *phc)
 			int muxed_rtcp = rtcp_demux(&phc->s, phc->mp.media);
 			if (muxed_rtcp == 2) {
 				is_rtcp = 1;
-				phc->in_srtp = phc->mp.stream->rtcp_sibling; // use RTCP SRTP context
+				if (phc->mp.stream->rtcp_sibling)
+					phc->in_srtp = phc->mp.stream->rtcp_sibling; // use RTCP SRTP context
 			}
 		}
 		if (is_rtcp) {