Importato causa 16 su reason Q850
Index: asterisk-13.21.1/res/res_pjsip_rfc3326.c
===================================================================
--- asterisk-13.21.1.orig/res/res_pjsip_rfc3326.c
+++ asterisk-13.21.1/res/res_pjsip_rfc3326.c
@@ -94,12 +94,13 @@ static void rfc3326_incoming_response(st
 static void rfc3326_add_reason_header(struct ast_sip_session *session, struct pjsip_tx_data *tdata)
 {
 	char buf[20];
-
+	int reason;
 	if (ast_channel_hangupcause(session->channel) == AST_CAUSE_ANSWERED_ELSEWHERE) {
 		ast_sip_add_header(tdata, "Reason", "SIP;cause=200;text=\"Call completed elsewhere\"");
 	}
-
-	snprintf(buf, sizeof(buf), "Q.850;cause=%i", ast_channel_hangupcause(session->channel) & 0x7f);
+	reason=ast_channel_hangupcause(session->channel);
+	if (reason==0) reason=16;
+	snprintf(buf, sizeof(buf), "Q.850;cause=%i", reason & 0x7f);
 	ast_sip_add_header(tdata, "Reason", buf);
 }