XMPP asmack: Contact presence not working for transitions to "available" - xmpp

Question

I am using asmack 8-0.8.3.
I don't receive messages for changes of Presence from my contacts when they move to "available".
If one contact passes from "available" to "dnd", I do receive a message. But not in the other way around.
Contact passes: "available" --> "dnd" --> "available" --> "dnd"
I receive: Presence{dnd} Presence{dnd}
Whereas I expect to receive a Presence update {available} between the 2 dnd.
Since I receive presence updates except for "available" I suppose my listener works fine. Also I suppose I correctly subscribed to my contacts' presence...
private class FriendListener implements RosterListener {
public void entriesAdded(Collection<String> addresses) { }
public void entriesUpdated(Collection<String> addresses) { }
public void entriesDeleted(Collection<String> addresses) { }
public void presenceChanged(Presence presence) {
String fromUserID = StringUtils.parseBareAddress(presence.getFrom());
System.out.println(
"Presence changed: " + fromUserID +
" Presence=" + presence.toString() +
" Type=" + presence.getType().toString() +
" Mode=" + presence.getMode().toString()
);
mainCallback_.updatePresenceFriend(fromUserID, presence);
}
}
public void subscribe(String friendID, String friendName) {
Presence presence = new Presence(Presence.Type.subscribe);
connection.sendPacket(presence);
RosterPacket rosterPacket = new RosterPacket();
rosterPacket.setType(IQ.Type.SET);
Item item = new Item(friendID, friendName);
item.setItemType(RosterPacket.ItemType.both);
rosterPacket.addRosterItem(item);
connection.sendPacket(rosterPacket);
System.out.println("Send subscribe to " + friendID);
subscribedUsers.add(friendID);
}

Answer 1

I found the problem!
Actually there was a bug in the log of my Listener, this line:
System.out.println(
"Presence changed: " + fromUserID +
" Presence=" + presence.toString() +
" Type=" + presence.getType().toString() +
" Mode=" + presence.getMode().toString()
);
It made crashed when Presence.getMode()==null, so that I did not process the Presence message. But no coredump was showing in the logs, I guess because the listener is in another thread...
Changing the log by the following line solved the problem
System.out.println(
"Presence changed: " + fromUserID +
" Presence=" + presence.toString()
);