Fixed ticket #845: Crash in 100rel after CANCEL is received and 487 is sent (thanks Gang Liu for the report)

git-svn-id: https://svn.pjsip.org/repos/pjproject/trunk@2697 74dad513-b988-da41-8d7b-12977e46ad98
diff --git a/pjsip/src/pjsip-ua/sip_inv.c b/pjsip/src/pjsip-ua/sip_inv.c
index 4966da5..fc48944 100644
--- a/pjsip/src/pjsip-ua/sip_inv.c
+++ b/pjsip/src/pjsip-ua/sip_inv.c
@@ -2480,7 +2480,12 @@
 	if (status == PJ_SUCCESS) {
 	    /* Remove the message body */
 	    tdata->msg->body = NULL;
-	    pjsip_dlg_send_response(inv->dlg, invite_tsx, tdata);
+	    if (inv->options & PJSIP_INV_REQUIRE_100REL) {
+		status = pjsip_100rel_tx_response(inv, tdata);
+	    } else {
+		status = pjsip_dlg_send_response(inv->dlg, invite_tsx, 
+						 tdata);
+	    }
 	}
     }