res_pjsip_session: Don't invoke session supplements twice for BYE requests.

When a BYE request is received the PJSIP invite session implementation
creates and sends a 200 OK response before we are aware of it. This
causes the INVITE session state callback to be called into and ultimately
the session supplements run on the BYE request. Once this response has
been sent the normal transaction state callback is invoked which
invokes the session supplements on the BYE request again. This can
be problematic in particular with res_pjsip_rfc3326 as it may
attempt to update the hangup cause code on the channel while it is
in the process of being hung up.

This change makes it so the session supplements are only invoked
once by the INVITE session state callback.

ASTERISK-25318 #close

Change-Id: I69c17df55ccbb61ef779ac38cc8c6b411376c19a

res/res_pjsip_session.c

@@ -2422,8 +2422,16 @@ static void session_inv_on_tsx_state_changed(pjsip_inv_session *inv, pjsip_trans
 		break;
 	case PJSIP_EVENT_RX_MSG:
 		cb = ast_sip_mod_data_get(tsx->mod_data, session_module.id, MOD_DATA_ON_RESPONSE);
-		handle_incoming(session, e->body.tsx_state.src.rdata, e->type,
-				AST_SIP_SESSION_AFTER_MEDIA);
+		/* As the PJSIP invite session implementation responds with a 200 OK before we have a
+		 * chance to be invoked session supplements for BYE requests actually end up executing
+		 * in the invite session state callback as well. To prevent session supplements from
+		 * running on the BYE request again we explicitly squash invocation of them here.
+		 */
+		if ((e->body.tsx_state.src.rdata->msg_info.msg->type != PJSIP_REQUEST_MSG) ||
+			(tsx->method.id != PJSIP_BYE_METHOD)) {
+			handle_incoming(session, e->body.tsx_state.src.rdata, e->type,
+							AST_SIP_SESSION_AFTER_MEDIA);
+		}
 		if (tsx->method.id == PJSIP_INVITE_METHOD) {
 			if (tsx->role == PJSIP_ROLE_UAC) {
 				if (tsx->state == PJSIP_TSX_STATE_COMPLETED) {