Fix the history numbers when re-joining a room

the <history/> element had a xmlns="" instead of the proper namespace.

src/core.py

@@ -1682,7 +1682,8 @@ class Core(object):
         if histo_length is not None:
             histo_length= str(histo_length)
         if tab and not tab.joined:
-            seconds = (int(time.time()) - tab.last_connection) if tab.last_connection != 0 else 0
+            seconds = (datetime.now() - tab.last_connection).total_seconds() if tab.last_connection is not None else 0
+            seconds = int(seconds)
             muc.join_groupchat(self.xmpp, room, nick, password,
                                histo_length, current_status.message, current_status.show, seconds=seconds)
         if not tab:

src/multiuserchat.py

@@ -73,7 +73,7 @@ def join_groupchat(xmpp, jid, nick, passwd='', maxhistory=None, status=None, sho
             passelement = ET.Element('password')
             passelement.text = passwd
             x.append(passelement)
-        history = ET.Element('history')
+        history = ET.Element('{http://jabber.org/protocol/muc}history')
         history.attrib['seconds'] = str(seconds)
         x.append(history)
         stanza.append(x)

src/tabs.py

@@ -654,7 +654,6 @@ class MucTab(ChatTab):
         self.info_header = windows.MucInfoWin()
         self.input = windows.MessageInput()
         self.ignores = []       # set of Users
-        self.last_connection = 0
         # keys
         self.key_func['^I'] = self.completion
         self.key_func['M-u'] = self.scroll_user_list_down
@@ -691,6 +690,13 @@ class MucTab(ChatTab):
     def general_jid(self):
         return self.get_name()
 
+    @property
+    def last_connection(self):
+        last_message = self._text_buffer.last_message
+        if last_message:
+            return last_message.time
+        return None
+
     @refresh_wrapper.always
     def go_to_next_hl(self):
         """
@@ -1538,7 +1544,6 @@ class MucTab(ChatTab):
         Set the state of the room as not joined, so
         we can know if we can join it, send messages to it, etc
         """
-        self.last_connection = int(time.time())
         self.users = []
         if self is not self.core.current_tab():
             self.state = 'disconnected'

src/text_buffer.py

@@ -35,6 +35,11 @@ class TextBuffer(object):
     def add_window(self, win):
         self.windows.append(win)
 
+    @property
+    def last_message(self):
+        return self.messages[-1] if self.messages else None
+
+
     def make_message(self, txt, time, nickname, nick_color, history, user, identifier, str_time=None):
         time = time or datetime.now()
         if txt.startswith('/me '):