Hi,
if I send a disco info to the latest Spark 2.6.3 client, it returns only this:
<iq id="123" to="..." type="result" from=".../Spark 2.6.3"><query xmlns="http://jabber.org/protocol/disco#info"><identity category="client" name="Smack" type="pc"/><feature var="http://www.xmpp.org/extensions/xep-0166.html#ns"/><feature var="urn:xmpp:tmp:jingle"/></query></iq>
This is of course problematic, if a client wants to discover Spark's features and only gets those two (which afaik aren't even registered XMPP namespaces).
Basically this means that Spark appears as feature-less client to other clients, which is of course undesirable, because the other clients would usually disable support for features with entities using a Spark client.
E.g. they won't have an "Invite to MUC" button for Spark users, because they assume that it's not supported anyway, see http://xmpp.org/extensions/xep-0045.html#disco-client
Just wanted to mention it, if somebody wants to fix it.