Bug 807631 - Receiving multi-part SMS doesn't work. r=philikon.

dom/system/gonk/ril_worker.js

@@ -3866,7 +3866,7 @@ let RIL = {
       this.sendDOMMessage(message);
     }
 
-    if (message.messageClass == GECKO_SMS_MESSAGE_CLASSES[PDU_DCS_MSG_CLASS_2]) {
+    if (message && message.messageClass == GECKO_SMS_MESSAGE_CLASSES[PDU_DCS_MSG_CLASS_2]) {
       // `MS shall ensure that the message has been to the SMS data field in
       // the (U)SIM before sending an ACK to the SC.`  ~ 3GPP 23.038 clause 4
       return PDU_FCS_RESERVED;