--- a/src/core/xmpp.py	Mon Mar 31 12:23:13 2014 +0200
+++ b/src/core/xmpp.py	Mon Mar 31 12:24:20 2014 +0200
@@ -286,7 +286,7 @@
         self.host = host
 
     def send(self, obj):
-        if not self.host.trigger.point("Presence send", obj):
+        if not self.host.trigger.point("Presence send", self.parent, obj):
             return
         super(SatPresenceProtocol, self).send(obj)
 

--- a/src/plugins/plugin_xep_0115.py	Mon Mar 31 12:23:13 2014 +0200
+++ b/src/plugins/plugin_xep_0115.py	Mon Mar 31 12:24:20 2014 +0200
@@ -33,6 +33,7 @@
 
 PRESENCE = '/presence'
 NS_ENTITY_CAPABILITY = 'http://jabber.org/protocol/caps'
+NS_CAPS_OPTIMIZE = 'http://jabber.org/protocol/caps#optimize'
 CAPABILITY_UPDATE = PRESENCE + '/c[@xmlns="' + NS_ENTITY_CAPABILITY + '"]'
 
 PLUGIN_INFO = {
@@ -61,11 +62,25 @@
 
     def _checkHash(self, disco_d, profile):
         if XEP_0115.cap_hash is None:
+            disco_d.addCallback(lambda dummy: self.host.hasFeature(NS_CAPS_OPTIMIZE, profile_key=profile))
+            def updateOptimize(optimize):
+                client = self.host.getClient(profile)
+                client.caps_optimize = optimize
+                if optimize:
+                    info(_("Caps optimisation enabled"))
+                    client.caps_sent = False
+                else:
+                    warning(_("Caps optimisation not available"))
+            disco_d.addCallback(updateOptimize)
             disco_d.addCallback(lambda dummy: self.recalculateHash(profile))
         return True
 
-    def _presenceTrigger(self, obj):
+    def _presenceTrigger(self, client, obj):
         if XEP_0115.cap_hash is not None:
+            if client.caps_optimize:
+                if client.caps_sent:
+                    return True
+                client.caps_sent = True
             obj.addChild(XEP_0115.c_elt)
         return True
 
@@ -82,6 +97,8 @@
         c_elt['ver'] = cap_hash
         XEP_0115.cap_hash = cap_hash
         XEP_0115.c_elt = c_elt
+        if client.caps_optimize:
+            client.caps_sent = False
         if cap_hash not in self.host.memory.disco.hashes:
             self.host.memory.disco.hashes[cap_hash] = disco_infos
             self.host.memory.updateEntityData(client.jid, C.ENTITY_CAP_HASH, cap_hash, profile)
@@ -99,7 +116,7 @@
         self.xmlstream.addObserver(CAPABILITY_UPDATE, self.update)
 
     def getDiscoInfo(self, requestor, target, nodeIdentifier=''):
-        return [disco.DiscoFeature(NS_ENTITY_CAPABILITY)]
+        return [disco.DiscoFeature(NS_ENTITY_CAPABILITY), disco.DiscoFeature(NS_CAPS_OPTIMIZE)]
 
     def getDiscoItems(self, requestor, target, nodeIdentifier=''):
         return []