fixup bcb9690 (Roster versioning)

1 files changed, 4 insertions, 4 deletions

diff --git a/xmpp-vala/src/module/xep/0199_ping.vala b/xmpp-vala/src/module/xep/0199_ping.vala
index 3b11bd73..6cb3b4ba 100644
--- a/xmpp-vala/src/module/xep/0199_ping.vala
+++ b/xmpp-vala/src/module/xep/0199_ping.vala
@@ -8,7 +8,7 @@ namespace Xmpp.Xep.Ping {
     public class Module : XmppStreamModule {
         public static ModuleIdentity<Module> IDENTITY = new ModuleIdentity<Module>(NS_URI, "0199_ping");
 
-        public void send_ping(XmppStream stream, string jid, ResponseListener listener) {
+        public void send_ping(XmppStream stream, string jid, ResponseListener? listener) {
             Iq.Stanza iq = new Iq.Stanza.get(new StanzaNode.build("ping", NS_URI).add_self_xmlns());
             iq.to = jid;
             stream.get_module(Iq.Module.IDENTITY).send_iq(stream, iq, on_ping_response, listener);
@@ -35,9 +35,9 @@ namespace Xmpp.Xep.Ping {
             public void on_iq_set(XmppStream stream, Iq.Stanza iq) { }
         }
 
-        private static void on_ping_response(XmppStream stream, Iq.Stanza iq, Object o) {
-            ResponseListener listener = o as ResponseListener;
-            listener.on_result(stream);
+        private static void on_ping_response(XmppStream stream, Iq.Stanza iq, Object? o) {
+            ResponseListener? listener = o as ResponseListener;
+            if (listener != null) listener.on_result(stream);
         }
     }