Comment 10 for bug 270689

buzzdee (sebastia) wrote :

as it states here: http://tools.ietf.org/html/draft-ietf-xmpp-3921bis-08#section-5.2.5

The inclusion of the <thread/> element is OPTIONAL. Because the
   <thread/> element identifies the particular conversation thread to
   which a message belongs, a message stanza MUST NOT contain more than
   one <thread/> element.

Coccinella sends the thread element, but other clients may not. In case no thread element exists, we will always trigger an event, otherwise we will only trigger an event when we do not know the thread already.