Since adding the AST_CONTROL_SRCUPDATE frame type,

there are places where ast_rtp_new_source may be called
where the tech_pvt of a channel may not yet have an
rtp structure allocated. This caused a crash in chan_skinny,
which was fixed earlier, but now the same crash has been 
reported against chan_h323 as well. It seems that the best 
solution is to modify ast_rtp_new_source to not attempt to 
set the marker bit if the rtp structure passed in is NULL.

This change to ast_rtp_new_source also allows the removal
of what is now a redundant pointer check from chan_skinny.

(closes issue #13247)
Reported by: pj



git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@136062 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_skinny.c

@@ -2868,9 +2868,7 @@ static int skinny_indicate(struct ast_channel *ast, int ind, const void *data, s
 	case AST_CONTROL_PROCEEDING:
 		break;
 	case AST_CONTROL_SRCUPDATE:
-		if (sub->rtp) {
-			ast_rtp_new_source(sub->rtp);
-		}
+		ast_rtp_new_source(sub->rtp);
 		break;
 	default:
 		ast_log(LOG_WARNING, "Don't know how to indicate condition %d\n", ind);

main/rtp.c

@@ -2000,7 +2000,9 @@ int ast_rtp_settos(struct ast_rtp *rtp, int tos)
 
 void ast_rtp_new_source(struct ast_rtp *rtp)
 {
-	rtp->set_marker_bit = 1;
+	if (rtp) {
+		rtp->set_marker_bit = 1;
+	}
 	return;
 }