plugin XEP-0085: fixed bad use of threads resulting in delay and crash when stopping the backend.

src/plugins/plugin_xep_0085.py

@@ -29,8 +29,8 @@ try:
     from twisted.words.protocols.xmlstream import XMPPHandler
 except ImportError:
     from wokkel.subprotocols import XMPPHandler
-from threading import Timer
 from twisted.words.xish import domish
+from twisted.internet import reactor
 
 NS_XMPP_CLIENT = "jabber:client"
 NS_CHAT_STATES = "http://jabber.org/protocol/chatstates"
@@ -324,7 +324,7 @@ class XEP_0085(object):
             pass
 
 
-class ChatStateMachine:
+class ChatStateMachine(object):
     """
     This class represents a chat state, between one profile and
     one target contact. A timer is used to move from one state
@@ -372,12 +372,9 @@ class ChatStateMachine:
                 client.xmlstream.send(mess_data['xml'])
 
         self.state = state
-        if self.timer is not None:
-            self.timer.cancel()
 
         if transition["next_state"] and transition["delay"] > 0:
-            self.timer = Timer(transition["delay"], self._onEvent, [transition["next_state"]])
-            self.timer.start()
+            self.timer = reactor.callLater(transition["delay"], self._onEvent, transition["next_state"])
 
 
 class XEP_0085_handler(XMPPHandler):