res_pjsip_session.c: Reorganize ast_sip_session_terminate().

Change-Id: I68a2128bcba4830985d2d441e70dfd1ac5bd712b

res/res_pjsip_session.c

@@ -1794,17 +1794,24 @@ void ast_sip_session_terminate(struct ast_sip_session *session, int response)
 		response = 603;
 	}
 
-	if ((session->inv_session->state == PJSIP_INV_STATE_CONFIRMED) && session->inv_session->invite_tsx) {
+	switch (session->inv_session->state) {
+	case PJSIP_INV_STATE_NULL:
+		pjsip_inv_terminate(session->inv_session, response, PJ_TRUE);
+		break;
+	case PJSIP_INV_STATE_CONFIRMED:
+		if (session->inv_session->invite_tsx) {
 			ast_debug(3, "Delay sending BYE to %s because of outstanding transaction...\n",
 					ast_sorcery_object_get_id(session->endpoint));
 			/* If this is delayed the only thing that will happen is a BYE request so we don't
 			 * actually need to store the response code for when it happens.
 			 */
 			delay_request(session, NULL, NULL, NULL, 0, DELAYED_METHOD_BYE);
-	} else if (session->inv_session->state == PJSIP_INV_STATE_NULL) {
+			break;
-		pjsip_inv_terminate(session->inv_session, response, PJ_TRUE);
+		}
-	} else if (((status = pjsip_inv_end_session(session->inv_session, response, NULL, &packet)) == PJ_SUCCESS)
+		/* Fall through */
-		&& packet) {
+	default:
+		status = pjsip_inv_end_session(session->inv_session, response, NULL, &packet);
+		if (status == PJ_SUCCESS && packet) {
 			struct ast_sip_session_delayed_request *delay;
 
 			/* Flush any delayed requests so they cannot overlap this transaction. */
@@ -1818,6 +1825,8 @@ void ast_sip_session_terminate(struct ast_sip_session *session, int response)
 				ast_sip_session_send_request(session, packet);
 			}
 		}
+		break;
+	}
 }
 
 static int session_termination_task(void *data)